EP3797276B1 - Leak detection device - Google Patents

Leak detection device Download PDF

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Publication number
EP3797276B1
EP3797276B1 EP19740609.3A EP19740609A EP3797276B1 EP 3797276 B1 EP3797276 B1 EP 3797276B1 EP 19740609 A EP19740609 A EP 19740609A EP 3797276 B1 EP3797276 B1 EP 3797276B1
Authority
EP
European Patent Office
Prior art keywords
detection
detection chamber
zone
sealing lip
membrane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP19740609.3A
Other languages
German (de)
French (fr)
Other versions
EP3797276A2 (en
Inventor
Gaël TOS
Sébastien LARROQUE
Carlos DA CUNHA
David HASSLER
Olivier Perrot
Anthony DE FARIA
Vincent Fraysse
Charles GIMBERT
Bruno Deletre
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gaztransport et Technigaz SA
Original Assignee
Gaztransport et Technigaz SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FR1870586A external-priority patent/FR3079300B1/en
Priority claimed from PCT/FR2019/050623 external-priority patent/WO2019180373A1/en
Application filed by Gaztransport et Technigaz SA filed Critical Gaztransport et Technigaz SA
Publication of EP3797276A2 publication Critical patent/EP3797276A2/en
Application granted granted Critical
Publication of EP3797276B1 publication Critical patent/EP3797276B1/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
    • G01M3/202—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material using mass spectrometer detection systems
    • G01M3/205—Accessories or associated equipment; Pump constructions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
    • G01M3/22—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
    • G01M3/225—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators for welds
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M3/00—Investigating fluid-tightness of structures
    • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
    • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
    • G01M3/20—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material
    • G01M3/22—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators
    • G01M3/226—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using special tracer materials, e.g. dye, fluorescent material, radioactive material for pipes, cables or tubes; for pipe joints or seals; for valves; for welds; for containers, e.g. radiators for containers, e.g. radiators

Definitions

  • the invention relates to a leak detection bell for detecting leaks from a sealing membrane, in particular from a corrugated sealing membrane, for example in a sealed tank.
  • sealed tanks can for example be sealed and thermally insulating tanks for storing and/or transporting a fluid, such as a cryogenic fluid.
  • the document KR1020100050128 discloses a method for testing the tightness of a membrane of a sealed and thermally insulating LNG storage tank.
  • the tank comprises a multilayer structure and has successively, from the outside inwards, a secondary insulating space, a secondary sealing membrane, a primary insulating space and a primary sealing membrane intended to be in contact with the gas. natural liquid contained in the tank.
  • the method aims more particularly at detecting leaks through the weld beads which make it possible to connect the metal sheets of the primary sealing membrane in a sealed manner.
  • the method provides for injecting a tracer gas into the primary insulating space and then moving detection equipment equipped with a tracer gas analyzer, inside the tank, along the welding seams of the membrane of primary sealing.
  • the detection equipment detects the presence of the tracer gas, it can be concluded that there is a leak in the primary sealing membrane.
  • the injection of the tracer gas into the primary insulating space is critical since the detection process can only guarantee reliable results if the tracer gas has diffused homogeneously throughout the entire primary insulating space. .
  • the detection equipment is composed of a tracer gas suction unit and a tracer gas detector.
  • the suction unit is moved by means of a carriage along the weld bead, the carriage being located on a bottom wall of the tank and the suction unit being fixed to the carriage so as to be on a weld bead of a wall adjacent to the bottom wall.
  • This equipment is also very slow because the equipment only checks a small portion of the weld bead at a time and it is necessary to modify the assembly of the equipment to the cart to change the weld bead.
  • the document EP3417259 describes a vacuum bell for detecting leaks in underground gas pipes.
  • the vacuum bell includes a flexible suction cup having a bottom forming a suction opening.
  • the bottom includes a flexible sealing ring surrounding the suction opening and forming a suitable contact surface to create a seal.
  • the document JP2017227530 describes a partial pressurization device for detecting a defect in the welding of a workpiece to a metal surface.
  • the partial pressurization device comprises a pressurization container part which comprises pressurizing means, a structure part comprising suction means, and a sealing means for maintaining a pressure difference at the point of contact with the surface. to measure.
  • An idea underlying the invention is to propose a detection bell or a leak detection device making it possible to test the tightness of a sealed membrane of a tank which is reliable and easily usable in the tank.
  • Another idea at the basis of the invention is to propose a detection bell or a leak detection device which can be used quickly, making it possible to test the tightness of a sealed membrane of a tank in a minimum of time.
  • Another idea underlying the invention is to propose a method for testing the tightness of a membrane which is reliable and quick to implement.
  • Certain aspects of the invention relate to a leak detection bell, in particular for detecting a leak on a test zone of a sealing membrane of a sealed and thermally insulating tank, the bell comprising a main body intended to be disposed over a test area and a seal bonded to the main body and configured to define a sensing chamber between the main body and the test area, the seal comprising a peripheral sealing lip configured to come in contact with the sealing membrane and having a closed contour surrounding the detection chamber.
  • Certain aspects of the invention relate to a method of using such a leak detection device or such a leak detection bell to detect a leak on a test zone of a waterproofing membrane of a watertight and thermally insulating tank.
  • the sealing lip has a flexibility allowing the formation of said pinching portion by deformation of the sealing lip in the direction of the detection chamber under the effect of the depression in the detection chamber.
  • the detection chamber of the leak detection bell has a convex zone, for example circular or in the shape of a polygon, intended to cover a junction zone between four corrugated or flat metal sheets.
  • a circle geometrically inscribed in the convex zone has a diameter greater than 68 mm.
  • the detection bell has an elongated shape along a longitudinal axis, the detection chamber of the leak detection bell having an elongated zone intended to cover a straight edge of a metal sheet, the convex zone being disposed at one end of the elongated zone.
  • the convex zone is a first convex zone and the detection chamber of the leak detection bell has a second convex zone arranged at one end of the elongated zone opposite to the first convex zone along the longitudinal axis.
  • the detection bell has an elongated shape along a longitudinal axis, the convex zone constituting a central portion of the detection chamber of the leak detection bell, the detection chamber having two elongated zones extending from the convex area opposite each other along the longitudinal axis.
  • the detection chamber has a circular or convex polygonal shape.
  • a circle geometrically inscribed in the shape of the detection chamber has a diameter greater than 68 mm.
  • the detection bell further comprises at least one handling handle arranged on an upper surface of the detection bell facing away from the sealing lip.
  • the detection bell comprises two handling handles arranged on the upper surface close to the two longitudinal ends of the detection bell.
  • the or each handling handle is arranged on an upper surface of the detection bell facing away from the sealing lip.
  • the analysis equipment includes a mass spectrometer.
  • such a bell may have one or more of the following characteristics.
  • the detection bell can be quickly placed on a test area so that the gasket can form a detection chamber over the entire test area.
  • the mechanical pressure means makes it possible to press the sealing lip on one or more portions, in particular where there is a risk that the seal will detach from the sealing membrane, in order to make the detection more reliable. of a possible leak through the detection bell.
  • the detection bell is capable of detecting a tracer gas having been injected for the purposes of the test, for example helium, or a gas from the ambient air.
  • this tracer gas is not necessarily injected into the zone whose sealing test, it can be in the zone in another way.
  • ambient air is meant a gaseous phase having a composition close to ambient dry air, that is to say comprising approximately 78% nitrogen, 21% oxygen, 0.9% argon as well as rare gases and volatile organic compounds likely to be emitted by an adhesive used in the thermally insulating barrier or originating from the solid insulating materials.
  • the pressure element is an elastically deformable element which exerts pressure on the portion of the sealing lip by elastic deformation.
  • the elasticity of the pressure element makes it possible, during its elastic deformation, to exert a return force on the sealing lip towards the sealing membrane.
  • the pressure element is oriented perpendicular to the contour of the peripheral sealing lip.
  • the sealing lip has a service state, when a vacuum is applied in the detection chamber, and a pinching portion of the sealing lip is maintained between the main body and the membrane of sealing over at least part of the periphery of the detection chamber, advantageously over the entire periphery of said chamber.
  • the leak detection bell has an elongated shape with a length greater than or equal to 0.5 m, preferably greater than or equal to 1 m, more preferably greater than or equal to 2 m.
  • the leak detection bell may have a width of between 10 and 20 centimeters (cm), preferably between 14 cm and 16 cm.
  • the weight of such a detection bell may be between 3 kilos and 25 kilos, preferably between 5 and 10 kilos, depending in particular on the materials used, its length and its width.
  • the mechanical pressure means comprises a plurality of pressure elements configured to exert pressure on a plurality of portions of the sealing lip, portions being located at the two ends of the sealing lip in a longitudinal direction.
  • portions of the sealing lip pressed by the mechanical pressure means are located at both ends of the sealing lip in a longitudinal direction, either at the two ends of the bell given that the latter has a generally longitudinal shape.
  • the mechanical pressure means applies pressure to different areas where there is a risk of the seal detaching, namely the ends of the seal.
  • the sealing lip comprises at least one indentation having a shape corresponding to that of an undulation of the membrane, the indentation being intended to span the undulation.
  • the sealing lip comprises at least two notches, for example three notches.
  • the leak detection bell is thus suitable, when it is used on a zone of membrane comprising waves, to test the weld zones present on a plurality of waves, for example at least three (3) waves and up to nearly a dozen waves. It may also be envisaged to associate several detection bells next to each other, or one after the other, in order to form a longer test zone length. According to one embodiment, a single vacuum pump can be used to generate the required vacuum in leak detection bells associated with each other.
  • a portion of the sealing lip pressed by the mechanical pressure means is located at a base of the notch.
  • the mechanical pressure means applies pressure to an area where there is a risk of the seal detaching due to the change in slope of the notch.
  • the mechanical pressure means comprises a plurality of pressure elements configured to exert pressure on a plurality of portions of the sealing lip, portions being located at the bases of the notch or notches.
  • the mechanical pressure means applies pressure to different areas where there is a risk of the seal detaching, namely the base of the indentations.
  • the portion of the sealing lip is located on a top of the notch.
  • all the portions of the sealing lip located at the bases of the indentation are pressed by the plurality of pressure elements of the mechanical means.
  • At least one of, part of or the pressure elements comprise a curved blade, at least one of the ends of which comes into abutment on the base of an indentation
  • At least one of, part of or the pressure elements comprise a curved blade whose two ends come into abutment on the base of two contiguous notches.
  • the positioning of the leak detection bell is made easier because the curved blade will allow the adequate placement under pressure of the indentations of the sealing lip on the two contiguous waves of the membrane, whatever the possible slight variations in the distance between these two contiguous waves or the approximate positioning of the leak detection bell on the wave membrane by one or more operators.
  • a support element extends over the entire length of the main body above it and is fixed to the main body.
  • the curved blades are distributed over the sealing lip and are fixed by fixing means to the support element.
  • the curved blades are elastically deformable so as to, when they are deformed, exert an elastic return force on the sealing lip.
  • the fixing means comprise a plurality of pins, the pins each comprising a rod mounted to move on a body, the rod comprising one end resting against one of the curved blades, the body being fixed to the support member, and also comprising a spring connecting the rod to the body, the spring acting between the body and the rod to position the end of the rod to bear against the curved blade and the spring being configured to exert a restoring force on the curved blade so that the curved blade presses the sealing lip against the foot of an undulation.
  • the mechanical pressure means comprises a plurality of end pressure elements, the end pressure elements being located at both ends of the sealing lip in a longitudinal direction, i.e. at both ends of the bell since the latter has a longitudinal shape.
  • At least one or more end pressure elements comprise an end pin, the end pin comprising a rod movably mounted on a body, an elongated support element being fixed to one end of the rod, the elongated support element bearing against the sealing lip, and the body being fixed to the support element, the end pin also comprising a spring connecting the rod to the body, the spring acting between the body and the stem to position the elongated bearing member against the sealing lip, the spring being configured to exert a biasing force on the elongated bearing member such that the bearing member elongated presses the sealing lip against the area to be tested.
  • the second end is equipped with an elongated bearing element, the elongated bearing element being configured to transmit the springback force over a zone of the sealing lip corresponding to a length of the elongated support element.
  • the second end of a first end pin and the second end of a second end pin adjacent to the first end pin are fixed to each other using an elongated support element.
  • At least one or more end pressure elements comprise a plurality of adjustment elements forming a line of elements, the adjustment element comprising a rod extending in the direction of the lip of sealing and an adjustable end in a longitudinal direction of the rod so as to come into contact with the sealing lip after adjustment.
  • the pressure element comprises a curved blade comprising at one of its ends in contact with the sealing lip a cylindrical sleeve.
  • the cylindrical sleeve makes it possible to uniformly apply the pressure of the mechanical pressure means on a part of the sealing lip.
  • the sealing gasket comprises an envelope which at least partially covers the main body and which is fixed to the main body, the peripheral sealing lip being linked to the envelope so as to extend it and being curved opposite the main body.
  • the cylindrical sleeve comprises a direction of length, the direction of length of the cylindrical sleeve being substantially orthogonal to the casing so that the cylindrical sleeve extends from the casing to one end of the lip sealing.
  • the sealing lip comprises a curved part substantially orthogonal to the casing, the curved part having a cross-sectional dimension greater than or equal to 1 cm, preferably greater than or equal to 1.5 cm, of more preferably greater than or equal to 2 cm.
  • the seal is made of an elastomeric material having a hardness of between 20 and 50 shore A.
  • the seal is made of a material that is flexible enough to be deformed by the mechanical means of pressure.
  • the elastomeric material of the seal is chosen from elastomeric polyurethane and ethylene-propylene-diene rubber monomer (EPDM).
  • EPDM ethylene-propylene-diene rubber monomer
  • the elastomer material of the seal can also be silicone, nitrile or Viton ® .
  • the main body comprises a rigid core
  • the seal comprises an envelope applied hermetically against a peripheral wall of the rigid core.
  • the rigid core comprises a recess on a lower surface intended to be turned towards the test area.
  • the rigid core has a channel connecting the recess to an upper surface of the rigid core to connect a vacuum pump.
  • the leak detection bell is oriented over the test area so that a length of the leak detection bell is superimposed with the test area.
  • the test zone is part of a weld bead of the sealing membrane.
  • the leak detection bell makes it possible to check whether there is any defect on the weld bead which could cause a leak in the waterproofing membrane.
  • the test area is located on a corrugated sealing membrane.
  • the peripheral sealing lip is shaped to adapt to the geometry of said at least one undulation.
  • the portion of the weld bead is crossed by at least two undulations, for example three undulations, parallel to the membrane and the peripheral sealing lip is shaped to adapt to the geometry of said undulations.
  • the peripheral sealing lip comprises at least two indentations having a shape corresponding to that of an undulation of the membrane projecting towards the inside of the tank, said indentations being intended to span said undulation.
  • At least one corrugation of the membrane protrudes towards the inside of the tank, the detection bell being placed against the membrane so that the indentations span the corrugation.
  • the peripheral sealing lip comprises at least two projecting zones having a shape corresponding to that of an undulation of the membrane projecting towards the outside of the tank.
  • the detection bell is placed against the membrane so that the projecting zones fit into the undulation.
  • the detection chamber is placed under depression to an absolute pressure value of between 10 and 1000 Pa, preferably less than 100 Pa absolute.
  • the gaseous phase is analyzed for a period greater than or equal to 5 seconds.
  • variable representative of a quantity of gas in said gaseous phase is compared with a threshold and it is determined that the tightness of the portion of the weld bead is defective when the representative variable is greater said threshold.
  • the analysis equipment is configured to detect a tracer gas or to detect a component of the ambient air.
  • a leak detection device which can be used to detect leaks in various sealed assemblies, for example a welded assembly.
  • the welded assembly is a sealing membrane for a fluid tank.
  • a leak detection device 54 is used, as represented on the figure 1 .
  • the leak detection device 54 comprises a detection bell 55 which is intended to be placed against the internal face of the membrane 5, 8 facing a portion of the weld bead to be tested.
  • the detection bell 55 has an elongated shape and has a length of between 0.5 and 4 m, for example of the order of 1 m.
  • the length of the detection bell 55 is advantageously as long as possible so as to check the tightness of a larger zone during a single and unique test. Nevertheless, the choice of this length of the bell can be adapted according on the one hand to the dimensions of the membrane 5, 8 to be tested and on the other hand with a view to its maneuverability by a minimum of operator(s), preferably by a single operator.
  • An elongated shape is particularly suitable for testing an assembly of rectangular metal sheets, in which the weld beads essentially follow the straight edges of the sheets.
  • the detection bell 55 comprises a rigid main body 100 and a flexible seal 60 which are fixed to one another and which are arranged to define with the membrane 5.8 to be tested a sealed detection chamber 61 , arranged opposite the portion of the weld bead 62 to be tested.
  • the leak detection device 54 also comprises analysis equipment 56 which is connected to the detection chamber 61 and makes it possible to detect a predefined gas, for example a tracer gas or an ambient air gas present on the other side of the weldment to be tested. As soon as the analysis equipment 56 detects the predefined gas in a quantity greater than a threshold, it can be concluded that there is a leak in the portion of the weld bead 62 tested.
  • the analysis equipment 56 is a mass spectrometer.
  • the leak detection device 54 also comprises a vacuum pump 57 which is associated with said analysis equipment 56.
  • the vacuum pump 57 is connected, on the one hand, to the detection chamber of the detection bell 55 so as to to allow depression of the detection chamber and, on the other hand, to the analysis equipment 56 of so as to conduct the gas contained in the detection chamber 61 to the analysis equipment 56.
  • the vacuum pump 57 is connected to the detection bell 55 via a pipe 58 which is preferably flexible.
  • the pipe 58 is connected to a channel which is formed in the main body 100 and opens into the detection chamber 61.
  • the main body 100 comprises a rigid core 59 and the seal 60 comprises a casing 63 matching the shape of the rigid core 59 and a peripheral sealing lip 64 which extends the casing 63 downwards.
  • the casing has a bottom 63 which covers the upper surface of the rigid core 59 and a peripheral wall 74 which matches the periphery of the rigid core 59.
  • the bottom 63 has at least one hole, not shown, to which the pipe is connected in leaktight manner. 58 connected to the vacuum pump 57.
  • the rigid core 59 has on its lower surface 80 a recess 79 over the entire length of the rigid core 59.
  • the recess 79 allows during a depression of the detection chamber 61 to ensure, despite a lowering of the rigid core 59 towards the membrane 5, 8 due to a deformation of the sealing lip 64, that the test zone 62 is always in fluid contact with the detection chamber 61.
  • the rigid core 59 also includes a channel 82, not shown on the picture 2 because present only in a plane passing at the level of the pipe 58, making it possible to connect the recess 79 to an upper surface 81 of the rigid core 59.
  • the channel 82 makes it possible to put the detection chamber 61 in communication with the vacuum pump 57 and analysis equipment 56 via pipe 58.
  • the peripheral sealing lip 64 is curved towards the outside of the detection bell 55 and is thus configured to bend and press against the membrane 5, 8 when the sealed chamber 61 is placed under depression.
  • the peripheral sealing lip 64 has a section with the general shape of L.
  • the outwardly curved portion of the peripheral sealing lip 64 has a width of the order of 15 to 40 mm.
  • the peripheral sealing lip 64 is shaped to adapt to the geometry of the membrane 5, 8 along the weld bead to be tested. Also, on the picture 3 , the peripheral sealing lip 64 has notches 65 having a shape corresponding to that of the undulations of the membrane 5, 8 that the detection bell 55 is intended to span when it is in position against the portion of the weld bead 62 to test.
  • the seal 60 is advantageously made of an elastomeric material having a hardness of between 20 and 50 Shore A.
  • the seal is by example made of elastomeric polyurethane, EPDM rubber, silicone, nitrile or Viton ® .
  • the picture 3 also illustrates the median longitudinal axis 20 of the detection chamber 61 surrounded by the peripheral sealing lip 64.
  • the detection bell 55 may comprise a sighting device which is produced, on the picture 3 , in the form of two indicator spikes 21 which are placed at the two longitudinal ends of the detection bell and oriented in alignment with the median longitudinal axis 20. Alternatively, only one of the two indicator spikes 21 could be provided.
  • the indicator spikes 21 are here made in one piece with the peripheral sealing lip 64, which ensures that the indicator spikes 21 are in the immediate vicinity of the membrane 5, 8 and therefore limits the risk of sighting error by parallax.
  • the indicator spikes 21 can however be produced in other ways, for example in the form of inserts.
  • the indicator spikes 21 can be attached to other parts of the detection bell 55.
  • the figure 21 illustrates an optical sighting device consisting of two laser diodes 22 attached to the two longitudinal ends of the detection bell 55 and emitting light beams 23 also oriented in alignment with the median longitudinal axis 20.
  • the laser diode 22 can be placed on the peripheral sealing lip 64 or above the peripheral sealing lip 64, for example on a support element 73 which will be described below.
  • the light beam 23 is inclined slightly downwards to strike the membrane 5, 8 and thus limit the risk of sighting error by parallax.
  • the detection bell 55 is also equipped with a mechanical pressure means 66, which in this embodiment is a clamping system 66, capable of pressing the peripheral sealing lip 64 against the membrane 8 to be tested in such a way to guarantee the sealing of the detection chamber 61.
  • the clamping system 66 here comprises a clamp 67 at the level of each of the notches 65 of the peripheral sealing lip 64.
  • Each clamp 67 comprises two branches respectively arranged on either side other of the notch 65 and configured to apply a clamping force of the peripheral sealing lip 64 against the membrane 8.
  • the branches are configured to clamp the peripheral sealing lip 64 against the membrane of sealing, near the base of the corrugation.
  • the clamping system 66 further comprises, at each of the longitudinal ends of the detection bell 55, a finger 68, movable, which is configured to press against one of the ends longitudinal of the peripheral sealing lip 64 against the membrane 8.
  • the figure 5 illustrates a gasket 60 according to an alternative embodiment.
  • This seal 60 is shaped to adapt to a membrane 5 in which the corrugations protrude towards the outside of the tank.
  • a membrane is, for example, a secondary membrane 5 according to Mark V technology.
  • the peripheral sealing lip 64 includes projecting zones 69 intended to be inserted inside the undulations of the membrane 5.
  • a procedure for detecting a seal defect in a weld bead is as follows.
  • the detection bell 55 is placed facing the portion of the weld bead 62 to be tested, which runs along a straight edge of a rectangular sheet, as shown in the figure 6 .
  • the detection bell 55 is suitably centered with respect to the weld bead 62 so that the two lateral parts of the curved portion of the peripheral sealing lip 64 are arranged on either side of the weld bead 62.
  • the figure 6 also illustrates the sighting device, made here in the form of the two indicator tips 21, which are placed precisely in superposition of the weld bead 62 by the operator to thus align the median longitudinal axis 20 of the detection chamber with the bead weld 62.
  • the optical sighting device of the figure 21 it is the light beams 23 which will be placed precisely superimposed on the weld bead 62.
  • the figure 6 also schematically illustrates the contour 30 of the detection chamber 61, namely the sealed contact line between the peripheral sealing lip 64 and the membrane 5, 8.
  • the vacuum pump 57 is then put into operation in order to put the detection chamber 61 under vacuum and promote the migration of gas through the defective zones of the weld bead 62.
  • a flow of gas is conducted from the detection chamber 61 to the analysis equipment 56 and a leak rate ⁇ of the predefined gas, for example tracer gas, is measured for a minimum duration Tm.
  • the leak rate ⁇ is then compared to a threshold ⁇ s.
  • the detection bell 55 is then detached from the membrane 5, 8 by releasing the depression in the detection chamber 61, for example by opening a gas inlet 71 shown on the figure 7 . Then the detection bell 55 is arranged facing an adjacent portion of the weld bead 62 ensuring an overlap between the two portions successively tested so as to guarantee that the tightness of the weld bead 62 has been tested over the entire length. of said weld bead 62.
  • the pressure threshold below which the leak rate is measured is between 10 and 1000 Pa absolute, preferably lower at 100 Pa absolute.
  • the minimum duration for measuring the leak rate is 5 seconds and the threshold ⁇ s is of the order of 1.0.10 -6 Pa.m 3 .s -1 .
  • the figure 7 shows a leak detection device 54 according to another embodiment.
  • This embodiment differs from the embodiment described above in that it further comprises a homogenization chamber 70 which is arranged between the detection chamber 61 and the analysis equipment 56 and in that the detection bell 55 has a gas inlet 71.
  • the gas inlet 71 is equipped with a tap making it possible to establish or interrupt a flow of ambient air towards the detection chamber 61.
  • the homogenization chamber 70 is connected to one end of the detection chamber 61 while the gas inlet 71 is connected to the opposite end of the detection chamber 61.
  • the mode of operation of the leak detection device 54 is as follows.
  • the gas inlet valve 71 When the detection bell 55 is positioned opposite the portion of the weld bead 62 to be tested, the gas inlet valve 71 is closed and the vacuum pump 57 is put into operation in order to put the detection chamber 61 in depression. As soon as the pressure inside the detection chamber 61 drops below a pressure threshold Ps, the gas inlet valve 71 is opened and all of the gas previously contained in the sealed chamber is transferred towards the homogenization chamber 70.
  • the homogenization chamber 70 has a volume greater than that of the chamber of detection 61 and comprises for example a piston system making it possible to precisely suck up all the gas contained in the detection chamber 61.
  • the gas contained in the homogenization chamber 70 is then transferred in the direction of the analysis equipment 56 in order to determine a gas leak rate ⁇ .
  • Such an embodiment is advantageous in that it makes it possible to reduce the diffusion time of the gas inside the detection bell 55 and thus makes it possible to reduce the minimum duration of measurement. This is particularly advantageous when the time for the gas to migrate from one end to another of the detection bell 55 is likely to be long due to a significant length of the detection bell 55 and/or when the depression prevailing inside the detection chamber 61 is insufficient.
  • the figure 8 represents a detection bell 55 according to a third embodiment.
  • the detection bell 55 of the figure 8 is designed similarly to the detection bell 55 of the figure 4 but differs in particular concerning the mechanical pressure means 66.
  • the detection bell 55 comprises a main body 100 extending in a longitudinal direction, a flexible seal 60 fixed to the main body 100 and a mechanical means of pressure 66 carried by the main body and configured to exert a pressure directed towards the membrane 5, 8 on the seal 60.
  • the main body 100 comprises a rigid core 59.
  • the rigid core 59 comprises a channel 82 making it possible to connect a lower surface 80 to an upper surface 81 of the rigid core 59.
  • the channel 82 allows communication between the detection chamber 61 and the gas outlet 78.
  • the seal 60 comprises an envelope 63 fixed to the rigid core 59 by fastening means 110, for example consisting of a strapping surrounding the entire circumference of the rigid core 59 and of the seal 60 and fixing these two elements 59/ 60 to each other by means of a mechanical fixing element such as screws.
  • the seal 60 also includes a peripheral sealing lip 64 connected to the casing 63 and having a closed contour making it possible to surround the part of the weld bead 62 to be tested.
  • the peripheral lip 64 is moreover curved in the opposite direction to the main body 100 so as to have a part of the peripheral lip 64 substantially parallel to the membrane 5, 8.
  • the peripheral sealing lip 64 also has a plurality of indentations 65 spaced apart on its circumference, the notches 65 having the shape of the undulations of the membrane 5, 8 to be tested.
  • the notches 55 allow the detection bell 55 to adapt to the wavy shape of the membrane 5, 8.
  • the body main 100 and the carrier element 73 are in particular traversed by a gas outlet 78 allowing, when the depression of the detection chamber 61 to evacuate the gas.
  • a support element 73 extends over the entire length of the main body 100 above it and is fixed to the main body 100.
  • Handling handles 76 are fixed to the two longitudinal ends of the support element 73 so as to allow the manipulation of the detection bell 55 by an operator and possibly to actuate the mechanical means of pressure by an effort of the operator.
  • the mechanical pressure means 66 is composed of a plurality of pressure elements 72 which are in the form of curved blades 72 distributed over the sealing lip 64 and which are fixed by fixing means 77 to the support element. 73.
  • the curved blades 72 are elastically deformable so as to, when they are deformed, exert an elastic return force on the sealing lip 64 in order to press it against the membrane 5, 8.
  • curved blades 72 are located in particular at the bases of the notches 64 of the sealing lip 64 and at the longitudinal ends of the detection bell 55 on the sealing lip 64.
  • a plurality of curved blades 72 are fixed at one of their ends to the support element 73 while the other end is placed on the sealing lip 64. These blades 72 are in particular placed on the ends of the detection 55. Other curved blades 72 are fixed in their middle to the support element 73 while their two ends are placed on the sealing lip 64 so as to apply pressure to two different zones, these blades 72 being notably placed between two notches 65.
  • the curved blades 72 have at each of their ends in contact with the sealing lip 64 a cylindrical sleeve 75.
  • the cylindrical sleeve 75 allows in particular a homogeneous support on the sealing lip 64 avoiding any punching which could degrade the integrity of the sealing lip 64.
  • the cylindrical sleeve 75 extends in a direction orthogonal to the longitudinal direction of the main body 100.
  • the length of a cylindrical sleeve 75 is moreover substantially equal to the dimension of the part of the lip seal 64 projecting from the main body 100, in the direction in which the cylindrical sleeve 75 extends.
  • the cylindrical sleeve 75 allows the mechanical pressure means 66 to exert pressure effectively on the sealing lip.
  • the mechanical pressure means 66 When placing the leak detection bell 55 on the area to be tested, it must be ensured that the mechanical pressure means 66 seals the seal well. seal 60 to be able to test the tightness of the weld properly. A problem is therefore to ensure that the mechanical pressure means 66 plays its role well all around the peripheral sealing lip 64.
  • the zone to be tested and in particular at the ends of the detection bell 55 can be a zone junction between several corrugated metal sheets, for example four corrugated metal sheets, so that the area is not entirely flat but has levels making it difficult to flatten the seal 60.
  • the figure 13 shows a detection bell 55 according to a fourth embodiment where the mechanical pressure means 66 has been reinforced at the ends of the detection bell 55 to compensate for the unevenness of the zone.
  • the detection bell 55 of the figure 13 is designed similarly to the detection bell 55 of the figure 8 but differs in particular by the shape of the detection chamber which has two circular zones at the two longitudinal ends which are wider than a central rectilinear band. Other differences relate to the mechanical means of pressure 66.
  • the detection bell 55 of the figure 13 also comprises a main body 100 extending in a longitudinal direction, a flexible seal 60 fixed to the main body 100 and a mechanical pressure means 66 carried by the main body and configured to exert a pressure directed towards the membrane 5 , 8 on the seal 60.
  • the mechanical pressure means 66 here comprises pressure elements 72 and end pressure elements 87.
  • the pressure elements 72 each comprise a curved blade 72, at least one end of which comes into abutment on the base of a notch 62.
  • the curved blades 72 located between two contiguous notches comprise one of their ends which is located against the base of one of the notches 65 and the other of the ends which is located against the base of the other of the notches 65.
  • the pressure elements 72 are here, as illustrated in the figure 14 , fixed by fastening means 77 each comprising a pin 83.
  • the pins 83 each comprise a rod 85 movably mounted on a body 84.
  • the rod 85 has one end resting against one of the curved blades 72.
  • the body 84 is fixed to the support element 73.
  • the pin 83 also comprises a spring 86 connecting the rod 85 to the body 84, the spring 86 acting between the body 84 and the rod 85 in order to position the end of the rod 85 in abutment against the curved blade 72.
  • the spring 86 is configured to exert a return force on the curved blade 72 so that the curved blade 72 presses the sealing lip 64 against the root of the corrugation.
  • the end pressure elements 87 are located at both ends of the sealing lip 64 in a longitudinal direction, that is to say at the two ends of the leak detection bell 55 since the latter has a general shape longitudinal.
  • the end pressure elements 87 can be designed according to a plurality of distinct variants which may or may not be combined on the same leak detection bell 55. For the sake of conciseness, three variants of the end pressure elements 87 are illustrated on the figure 13 on the same leak detection bell 55.
  • the figures 15 to 17 represent the three variants of the end pressure elements 87.
  • the end pressure element 87 comprises an end pin 88.
  • the end pins 88 each comprise a rod 90 movably mounted on a body 89.
  • An elongated support element 91 is fixed to one end of the rod 90, the elongated support element 91 bearing against the sealing lip 64.
  • the body 89 is fixed to the support element 73.
  • the end pin 88 also comprises a spring 86 connecting rod 90 to body 89, spring 86 acting between body 89 and rod 90 to position elongated bearing member 91 against sealing lip 64.
  • spring 86 is configured to exert a force reminder on the elongated support element 91 so that the elongated support element 91 presses the sealing lip 64 against the area to be tested. In this way, the return force is exerted on the sealing lip 64 over the entire length of the elongated support element 91.
  • each elongated support element 91 is attached to only one rod 90 of an end pin 88.
  • a second variant of the end pressure elements 87 is illustrated in the figure 16 .
  • the second variant differs from the first variant by the elongated support element 91 of the end pins 88, the other characteristics of the end pressure elements 87 are retained.
  • the elongated support element 91 is fixed to one end of a rod 90 of a first end pin 88 and to one end of a rod 90 of a second adjacent end pin 88 to the first end pin 88.
  • the elongated support element 91 is therefore here longer than in the first variant and is thus pressed by two end pins 88 distributed over its length so as to form a support of one greater length on the sealing lip 64.
  • the end pressure element 87 comprises a plurality of adjustment elements 92 forming a line of elements.
  • the adjustment element 92 comprises a rod 93 extending in the direction of the sealing lip 64 and perpendicular to the zone to be tested and an end 94 whose position is adjustable in a longitudinal direction of the rod so as to come into contact with the sealing lip 64 after adjustment of the rod 93.
  • the figure 17 also illustrates a distribution sole 95 which can be arranged between the ends 94 of the rods 93 and the upper surface of the sealing lip 64, in order to limit the risk of puncturing of the sealing lip 64 and thus increase its durability.
  • the distribution plate 95 can be an elongated plate of generally straight shape or, as shown, arcuate to follow the contour of the sealing lip 64. Its material can be a rigid plastic resin.
  • sub-formed connecting sleeves protrude from the upper surface of the distribution sole 95 to accommodate the ends 94 and thus fix the distribution sole 95 with respect to the rods 93.
  • a leak detection bell 65 as illustrated in figure 8 in a leak detection device 54 comprising said bell 65, a vacuum pump 57 connected to the detection chamber 61 via the gas outlet 78 and analysis equipment 56.
  • the use of such a detection device 54 makes it possible to check the tightness of a weld bead 62 between two corrugated sheets of a sealing membrane 5, 8.
  • the detection bell 55 is placed on the area to be tested for leaktightness, here a part of the weld bead 62, for example by one or more operators via the handling handles 76.
  • the main body 100 of the detection bell 55 is placed above the weld bead 62 so that the length of the main body 100 is aligned with and centered on the weld bead 62. If necessary, an aiming device described above can be employed for this.
  • the sealing lip 64 is located on either side of the weld bead 62 and completely surrounds the area of the weld bead 62 to be tested to form with the main body 100 and the membrane 5, 8 a detection chamber 61 waterproof, as seen on the figure 9 .
  • the detection bell 55 After the detection bell 55 has been placed on the weld bead 62, the detection bell 55 is fixed like a suction cup on the membrane 5, 8 thanks to the depression force activated by the vacuum pump 57. This force of depression activates, if necessary, the mechanical pressure means 66 so that it redirects the pressure in order to press the sealing lip 64 on the membrane 5, 8 in certain well-defined areas.
  • the support element 73 When the mechanical pressure means 66 undergoes a force on the support element 73, the support element 73 retransmits the force to the curved blades 72 via their respective fixings which tends to elastically deform the curved blades 72. As a result and by elastic return, the curved blades 72 transmit the force to the sealing lip 64 via the cylindrical sleeves 75 to the zones where the detachment of the sealing lip is most likely, namely the longitudinal ends of the main body 100 and the bases indentations 65.
  • the vacuum pump 57 creates a depression in the detection chamber 61 via the channel 82 and the gas outlet 78.
  • the flexibility of the sealing lip 64 causes a deformation of the latter when the depression of the detection chamber 61 tending to reduce the volume of the detection chamber 61. Indeed, the sealing lip 64 thus approaches on either side of the weld bead 62 as visible on the figure 10 . As soon as the pressure inside the detection chamber 61 drops below a pressure threshold Ps, the gases present in the detection chamber 61 are led to the analysis equipment 56.
  • the analysis equipment 56 then analyzes during a measurement time Tm the gas concentration of the gases present in the detection chamber 61 so as to obtain a value representative of the change in concentration. This representative value is then compared with a threshold value so as to determine whether or not the part of the weld bead 62 tested has a sealing defect.
  • the detection bell 55 is then placed opposite an adjacent portion of the bead of weld 62 by ensuring an overlap between the two successively tested portions so as to guarantee that the tightness of the weld bead 62 has been tested over the entire length of said weld bead 62.
  • the measured value is greater than or equal to the threshold value, then it is concluded that the tested part of the weld bead 62 has a sealing defect. Corrective welding measures are then implemented to correct the defect. Measurements using an additional detection tool can also be envisaged so as to locate more precisely the location of the sealing defect.
  • the sealing lip 64 occupies two positions depending on whether it is in its initial state, either without the application of a vacuum in the detection chamber 61, or in its service state, when such vacuum is applied.
  • the sealing lip 64 rests without pressure on the surface of a sealing membrane 5, 8, while in its operating state at least one pinching portion 53 located at an inner end of the lip d sealing 64 is pressed under the main body 100 so as to perfectly seal the contour or the periphery of the detection chamber 61. Indeed, thanks to the flexibility of the sealing lip 64, it is pinched between the main body 100 and the membrane 5, 8 when the depression is applied. This positioning of the pinching portion 53 of the sealing lip 64 between the main body 100, crushed or compressed by the latter, and the sealing membrane 5, 8 effectively contributes to obtaining perfect sealing of the detection chamber 61, thus making it possible to obtain and maintain a vacuum of at most 1500 Pa (15 mbar), or even having a much lower pressure.
  • the sealing lip 64 has a service state, when a vacuum is applied in the detection chamber 61, in which a pinching portion 53 of the sealing lip 64 is maintained between the main body 100 and the sealing membrane 5, 8 over at least part of the periphery of the detection chamber 61, or even over the entire periphery of said chamber 61. Thanks to this pinching, it is possible to switch from all or part of the mechanical pressure means described above.
  • the peripheral sealing lip 64 is formed with the pinching portion 53 projecting permanently under the main body 100, that is to say also in the initial state without depression, for example while around the detection chamber 61 or over part of its periphery.
  • the area to be tested can be a junction area between several metal sheets, for example four rectangular metal sheets, corrugated or not.
  • Such use of the detection bell 55 will now be described with reference to the figures 18 to 20 .
  • each of the four rectangular metal sheets 31 has a cutaway 32 at the corner, for example forming an angle of 45° with the edges of the sheet.
  • the four cut sides 32 are approached to each other overlapping on a metal insert 33 fixed to the insulating block and of which a central zone, here of square shape, remains uncovered between the four cut sides 32.
  • This central zone of the insert metal 33 forms part of the waterproof membrane thanks to the waterproof weld lines made along the cut sides 32.
  • Lines 34 in dashed lines represent offset curvatures in the direction of thickness of the rectangular metal sheets 31 which allow mutual overlaps, according to the known technique.
  • the detection bell has a shape corresponding to the embodiment of the figure 13 .
  • the position of the detection bell has been sketched by representing the contour of the sealing lip 64 and the contour 30 of the chamber of detection 61, which is partially shown.
  • the circular zone 25 of the detection chamber 61 is positioned in line with the aforementioned junction zone, for example centered on the exposed part of the metal insert 33, while the central rectilinear strip 24 of the detection chamber 61 is positioned on a straight edge of one of the rectangular metal sheets 31.
  • the circular zone 25 of the detection chamber 61 has a diameter adapted to completely encompass the four cut sides 32 in line with the aforementioned junction zone. For this, its diameter is for example greater than 68 mm for a corrugated membrane of the Mark III ® type.
  • the end pressure elements 87 have been sketched in dashed lines. It can thus be noted that the end pressure elements 87 have been positioned on the detection bell so that, when the detection bell is positioned at this location, the end pressure elements 87 are in fact located at right weld beads 62 which join the rectangular metal sheets 31 together along the edges. Thus, the end pressure elements 87 bear on the portions of the peripheral sealing lip 64 which rest on these weld beads 62, which necessarily have a certain relief. The end pressure elements 87 thus positioned make it possible to obtain a perfectly sealed contact despite this relief. In particular, we see on the figure 18 that three end pressure elements 87 bear on three portions of the peripheral sealing lip 64 which respectively pass through three weld beads 62 of this junction zone.
  • the end pressure elements 87 illustrated in the figure 18 preferably have a rectilinear or curvilinear elongated shape. They can in particular be made in the form of elongated support elements 91 as on the figure 16 or with a 95 distribution sole as on the figure 17 .
  • the detection bell has a modified shape in which the circular zone 25 constitutes a central portion of the detection chamber 61 and the detection chamber 61 has two elongated zones 24 extending from the circular zone 25 in a diametrically opposite manner. from each other along the median longitudinal axis 20.
  • the detection bell has a modified shape in which the detection chamber 61 has a circular shape.
  • a convex polygonal shape can be used instead of the circular zone 25, in which case a circle geometrically inscribed in the shape of the detection chamber must have a diameter adapted to completely encompass the four cut sides 32 in line with the detection zone. aforementioned junction.
  • the leak detection device 54 comprises the detection bell 55, the analysis equipment 56 with its associated vacuum pump 57, possibly a second vacuum pump 37 of higher power, and a suction circuit connecting the chamber 61 to the analysis equipment 56 via a solenoid valve 48.
  • the suction circuit preferably comprises a flexible pipe 58 of sufficient length to promote the mobility of the detection bell 55 on a relatively large work area around the analysis equipment 56.
  • This flexible pipe 58 is for example connected by connectors 39, on the one hand to an outlet of the detection chamber 61 and on the other hand to the equipment 56.
  • a branch connection 38 may be provided to connect the analysis equipment 56 and the second vacuum pump 37 in branch from each other.
  • a control unit 36 is also provided to drive the solenoid valve 48, and possibly other elements such as the analysis equipment 56, in response to actions by an operator on one or more detection 55, for example arranged on one or more handling handles 76 of the detection bell 55.
  • the two handling handles 76 are each provided with a push button operable with the thumb and configured respectively as an activation button 51 and a deactivation button 52.
  • Control members having a shape other than a push button can be considered alternatively, for example a capacitive touch button, a tilting lever, or any other manually operable member.
  • the vacuum pump 37 or other source of depression is activated beforehand and permanently generates a depression in the suction circuit.
  • the solenoid valve 48 has a closed state by default, so that the detection chamber 61 is not initially subjected to the depression, which makes it possible to move the detection bell 55 freely on the membrane 5, 8.
  • control unit 36
  • step 41 an activation command signal issued by the activation button 51 is detected.
  • step 42 the solenoid valve 48 is switched to an open state to connect the detection chamber 61 to the vacuum pump 37.
  • This state can be signaled by the lighting of a luminous indicator on the detection bell 55 , for example a red LED, for example on the handling handle 76 as shown in figure 96 of the figure 15 .
  • step 45 a disable command signal from disable button 52 is detected.
  • the solenoid valve 48 is switched to a closed state to isolate the detection chamber 61 from the vacuum pump 37.
  • the depression in the detection chamber 61 is no longer maintained, which allows the pressure to go up. However, unless there is a large leak rate, this rise in pressure can be very slow.
  • a vent is therefore opened to place the detection chamber 61 in communication with the ambient atmosphere, which makes it possible to immediately release the detection bell 55 from the membrane 5, 8.
  • steps 46 and 47 are performed simultaneously by switching a three-way valve 148 shown schematically on the figure 25 , which is used instead of solenoid valve 48 of the figure 22 .
  • the solenoid valve 48 can be positioned on the gas outlet 78 of the detection bell 55, as illustrated in the figure 22 . It can also be positioned at another location in the suction circuit, for example at the branch connection 38 as indicated by the number 248.
  • control signals between the control unit 36, the solenoid valve 48 and the activation button 51 and deactivation button 52 are transported by wired or wireless communication links, for example made in the form of a flexible electrical cable or a braid of flexible cables to promote the mobility of the detection bell 55.
  • control unit 36 is configured to also control the analysis equipment 56.
  • a wired or wireless communication link 35 is also provided between the control unit 36 and the analysis equipment 56.
  • a pressure sensor 49 also connected to the control unit 36 is provided on the detection bell 55 to measure the pressure in the detection chamber 61 following step 42.
  • step 43 the pressure indicated by the measurement signal from the pressure sensor 49 is compared with a predefined pressure threshold to allow the operation of the analysis equipment 56. If the pressure measured is lower than this threshold, the step 44 is performed.
  • This state can be signaled by the lighting of another luminous indicator on the detection bell 55, for example a green LED, for example on the handling handle 76 as illustrated in figure 97 of the figure 15 .
  • step 44 the analysis equipment 56 is activated to carry out an analysis cycle making it possible to detect a leak rate, as explained above.
  • two channels 82 and 50 pass through the main body to connect the detection chamber 61 to two gas outlets 78 and 50.
  • the pressure sensor 49 can be placed on the detection bell 55 and connected to the gas outlet 50, as illustrated on the figure 22 .
  • the pressure sensor 49 could also be arranged at another position.
  • the use of the leak detection device 54 is particularly easy and rapid.
  • the source of depression being activated beforehand, the operator grasps the detection bell 55 by the two handles and positions the detection bell 55 on the chosen test zone, if necessary with the help of the sighting devices described above.
  • the operator only has to press the deactivation button 52 to position the detection bell 55 on another test zone.
  • the detection bell 55 can therefore be used without the operator needing to interact with the vacuum pump 37, the control unit 36 or the analysis equipment 56, in an entire defined work area. by the length of the fluidic and electrical connections of the detection bell 55 with these elements.
  • the vacuum pump 37, the control unit 36 and the analysis equipment 56 can be mounted on a rolling cart, not shown.
  • the different characteristics of the previous embodiments can be combined with one another.
  • the mechanical pressure means 66 of the figure 8 are adaptable to a gasket 60 of the figure 5 by modifying the arrangement of the curved blades 72.
  • the detection bell, the detection device and the method of using the device described above are aimed more particularly at testing the tightness of a membrane of a sealed and thermally insulating tank with membranes.
  • membrane tanks are described in particular in the patent applications WO14057221 , FR2691520 .
  • Membrane tanks have a plurality of walls that have a multi-layered structure, as shown in the figure 11 .
  • Each wall 1 comprises, from the outside towards the inside of the tank, a secondary thermally insulating barrier 2 comprising secondary insulating panels 3 anchored to a supporting structure 4, a secondary membrane 5 resting against the secondary thermally insulating barrier 2, a primary thermally insulating barrier 6 comprising primary insulating panels 7 resting against the secondary membrane 2 and anchored to the load-bearing structure 4 or to the secondary insulating panels 3 and a primary membrane 8 which rests against the primary thermally insulating barrier 6 and which is intended to be in contact with the liquefied gas contained in the tank.
  • the tank has a generally polyhedral shape.
  • the tank has a front wall 9 and a rear wall, not shown, which are octagonal in shape here.
  • the tank also comprises a ceiling wall 10, a bottom wall 11 and side walls 11, 12, 13, 14, 15, 16, 17 which extend along the longitudinal direction of the tank between the front wall 9 and the rear wall.
  • the secondary thermally insulating barriers 2 of the vessel walls communicate with each other so as to form, between the supporting structure 4 and the secondary membrane 5, a secondary thermally insulating, sealed space.
  • the primary thermally insulating barriers 6 of the vessel walls communicate with each other so as to form, between the secondary membrane 5 and the primary membrane 8, a primary, sealed, thermally insulating space.
  • At least one of the primary 8 and secondary 5 membranes comprises a plurality of metal sheets which are welded to each other.
  • the tightness test method which will be described later aims more particularly at testing the tightness of the welds making it possible to connect the metal sheets to each other.
  • the membrane to be tested has undulations which allow it to deform under the effect of the thermal and mechanical stresses generated by the fluid stored in the tank. To do this, as shown for example in the figure 8 , each metal sheet has two sets of corrugations perpendicular to each other.
  • the sealing test method comprises only the verification of the sealing of the welds of the membrane 5, 8 without the aid of tracer gas.
  • the step of diffusion of a tracer gas consists in injecting a tracer gas into the thermally insulating space which is covered by the membrane 5, 8 whose tightness is to be checked.
  • the tracer gas is injected into the secondary thermally insulating space.
  • the sealing test method is implemented before the primary thermally insulating barrier 7 and the primary membrane 8 are installed.
  • the tracer gas is injected into the primary thermally insulating space.
  • the figure 12 schematically illustrates a sealed and thermally insulating tank as well as a system for injecting tracer gas into a thermally insulating space.
  • the injection system comprises a plurality of ducts 18 which are, on the one hand, connected to a source of tracer gas, not shown, and, on the other hand, connected to tracer gas injection devices 19 providing a injection passage of the tracer gas through the membrane 5, 8 whose tightness must be tested. More particularly, the tracer gas injection devices 19 provide tracer gas passages through the membrane of the bottom wall 11. Such an arrangement is particularly advantageous because the tracer gas has a lower vapor density than that of the air so that it tends to rise in the thermally insulating space. Consequently, the injection of the tracer gas from below, through the membrane 5, 8 to be tested of the bottom wall 11, makes it possible to ensure rapid and homogeneous diffusion of the tracer gas in the thermally insulating space.
  • the bottom wall 11 is equipped with at least four tracer gas injection devices 19 which are evenly distributed over the surface of the bottom wall 11.
  • the bottom wall 11 has a rectangular shape and can thus be divided into four zones of equal surface by its two axes of symmetry x and y.
  • Each of the four tracer gas injection devices 19 is placed in one of the four aforementioned zones.
  • each tracer gas injection device 19 is arranged close to the center of its respective zone.
  • each of the four tracer gas injection devices is arranged at a distance 1 ⁇ 4 L from the adjacent longitudinal edge and at a distance 1 ⁇ 4 B from the adjacent transverse edge with L: the longitudinal dimension of the bottom wall 11 and B: the transverse dimension of the bottom wall 11.
  • the tracer gas diffusion control step consists in, when the tracer gas has diffused through the thermally insulating space, controlling the diffusion of the tracer gas in the thermally insulating space.
  • the gas contained in the thermally insulating space into which the tracer gas has been injected is sampled by means of a plurality of gas sampling devices provided through the membrane covering said thermally insulating space.
  • Each sampling device is connected to analysis equipment, such as a mass spectrometer, which makes it possible to verify the presence and the concentration of the tracer gas in the corresponding zone of the thermally insulating space.
  • the weld verification step consists of using the leak detection device 54, previously described, on one of the membranes 5, 8 of the sealed and thermally insulating tank.

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Description

Domaine techniqueTechnical area

L'invention se rapporte à une cloche de détection de fuite permettant de détecter des fuites d'une membrane d'étanchéité, en particulier d'une membrane d'étanchéité ondulée, par exemple dans une cuve étanche. Ces cuves étanches peuvent par exemple être des cuves étanches et thermiquement isolantes pour le stockage et/ou le transport d'un fluide, tel qu'un fluide cryogénique.The invention relates to a leak detection bell for detecting leaks from a sealing membrane, in particular from a corrugated sealing membrane, for example in a sealed tank. These sealed tanks can for example be sealed and thermally insulating tanks for storing and/or transporting a fluid, such as a cryogenic fluid.

Arrière-plan technologiqueTechnology background

Le document KR1020100050128 divulgue un procédé de test de l'étanchéité d'une membrane d'une cuve étanche et thermiquement isolante de stockage de GNL. La cuve comporte une structure multicouche et présente successivement, depuis l'extérieur vers l'intérieur, un espace isolant secondaire, une membrane d'étanchéité secondaire, un espace isolant primaire et une membrane d'étanchéité primaire destinée à être en contact avec le gaz naturel liquéfié contenu dans la cuve. Le procédé vise plus particulièrement à détecter des fuites au travers des cordons de soudure qui permettent de relier de manière étanche les tôles métalliques de la membrane d'étanchéité primaire. Le procédé prévoit d'injecter un gaz traceur dans l'espace isolant primaire puis de déplacer un équipement de détection équipé d'un analyseur de gaz traceur, à l'intérieur de la cuve, le long des cordons de soudure de la membrane d'étanchéité primaire. Ainsi, si l'équipement de détection détecte la présence du gaz traceur, il peut être conclu à un défaut d'étanchéité de la membrane d'étanchéité primaire. Dans un tel procédé, l'injection du gaz traceur dans l'espace isolant primaire est critique puisque le procédé de détection ne peut garantir des résultats fiables que si le gaz traceur a diffusé de manière homogène dans l'intégralité de l'espace isolant primaire.The document KR1020100050128 discloses a method for testing the tightness of a membrane of a sealed and thermally insulating LNG storage tank. The tank comprises a multilayer structure and has successively, from the outside inwards, a secondary insulating space, a secondary sealing membrane, a primary insulating space and a primary sealing membrane intended to be in contact with the gas. natural liquid contained in the tank. The method aims more particularly at detecting leaks through the weld beads which make it possible to connect the metal sheets of the primary sealing membrane in a sealed manner. The method provides for injecting a tracer gas into the primary insulating space and then moving detection equipment equipped with a tracer gas analyzer, inside the tank, along the welding seams of the membrane of primary sealing. Thus, if the detection equipment detects the presence of the tracer gas, it can be concluded that there is a leak in the primary sealing membrane. In such a process, the injection of the tracer gas into the primary insulating space is critical since the detection process can only guarantee reliable results if the tracer gas has diffused homogeneously throughout the entire primary insulating space. .

De plus, l'équipement de détection est composé d'une unité de succion du gaz traceur et d'un détecteur à gaz traceur. L'unité de succion est déplacée à l'aide d'un chariot tout au long du cordon de soudure, le chariot étant situé sur une paroi de fond de la cuve et l'unité de succion étant fixée au chariot de manière à se trouver sur un cordon de soudure d'une paroi adjacente à la paroi de fond. Cependant, il est difficile à l'aide de cet équipement de vérifier l'intégralité des cordons de soudure de la cuve car l'équipement est encombrant et nécessite d'être connecté au chariot sur la paroi de fond. Cet équipement est également très lent car l'équipement ne vérifie qu'une faible portion du cordon de soudure à la fois et il est nécessaire de modifier l'assemblage de l'équipement au chariot pour changer de cordon de soudure.In addition, the detection equipment is composed of a tracer gas suction unit and a tracer gas detector. The suction unit is moved by means of a carriage along the weld bead, the carriage being located on a bottom wall of the tank and the suction unit being fixed to the carriage so as to be on a weld bead of a wall adjacent to the bottom wall. However, it is difficult using this equipment to check all the weld beads of the tank because the equipment is bulky and needs to be connected to the trolley on the bottom wall. This equipment is also very slow because the equipment only checks a small portion of the weld bead at a time and it is necessary to modify the assembly of the equipment to the cart to change the weld bead.

Le document EP3417259 décrit une cloche à vide pour détecter des fuites dans des conduites de gaz souterraines. La cloche à vide comprend une coupe d'aspiration flexible ayant un fond formant une ouverture d'aspiration. Le fond comprend une bague d'étanchéité souple entourant l'ouverture d'aspiration et formant une surface de contact adaptée pour créer un joint.The document EP3417259 describes a vacuum bell for detecting leaks in underground gas pipes. The vacuum bell includes a flexible suction cup having a bottom forming a suction opening. The bottom includes a flexible sealing ring surrounding the suction opening and forming a suitable contact surface to create a seal.

Le document JP2017227530 décrit un dispositif de pressurisation partielle pour détecter un défaut dans la soudure d'une pièce sur une surface métallique. Le dispositif de pressurisation partielle comporte une partie conteneur de pressurisation qui comporte des moyens de pressurisation, une partie de structure comprenant des moyens d'aspiration, et un moyen d'étanchéité pour maintenir une différence de pression au niveau du point de contact avec la surface à mesurer.The document JP2017227530 describes a partial pressurization device for detecting a defect in the welding of a workpiece to a metal surface. The partial pressurization device comprises a pressurization container part which comprises pressurizing means, a structure part comprising suction means, and a sealing means for maintaining a pressure difference at the point of contact with the surface. to measure.

Résumé de l'inventionSummary of the invention

Une idée à la base de l'invention est de proposer une cloche de détection ou un dispositif de détection de fuite permettant de tester l'étanchéité d'une membrane étanche d'une cuve qui soit fiable et facilement utilisable dans la cuve.An idea underlying the invention is to propose a detection bell or a leak detection device making it possible to test the tightness of a sealed membrane of a tank which is reliable and easily usable in the tank.

Une autre idée à la base de l'invention est de proposer une cloche de détection ou un dispositif de détection de fuite qui est utilisable rapidement permettant de tester l'étanchéité d'une membrane étanche d'une cuve en un minimum de temps.Another idea at the basis of the invention is to propose a detection bell or a leak detection device which can be used quickly, making it possible to test the tightness of a sealed membrane of a tank in a minimum of time.

Une autre idée à la base de l'invention est de proposer un procédé de test de l'étanchéité d'une membrane qui soit fiable et rapide à mettre en œuvre.Another idea underlying the invention is to propose a method for testing the tightness of a membrane which is reliable and quick to implement.

Certains aspects de l'invention se rapportent à une cloche de détection de fuite, notamment pour détecter une fuite sur une zone de test d'une membrane d'étanchéité d'une cuve étanche et thermiquement isolante, la cloche comprenant un corps principal destiné à être disposé sur une zone de test et un joint d'étanchéité lié au corps principal et configuré pour définir une chambre de détection entre le corps principal et la zone de test, le joint d'étanchéité comportant une lèvre d'étanchéité périphérique configurée pour venir en contact avec la membrane d'étanchéité et présentant un contour fermé entourant la chambre de détection.Certain aspects of the invention relate to a leak detection bell, in particular for detecting a leak on a test zone of a sealing membrane of a sealed and thermally insulating tank, the bell comprising a main body intended to be disposed over a test area and a seal bonded to the main body and configured to define a sensing chamber between the main body and the test area, the seal comprising a peripheral sealing lip configured to come in contact with the sealing membrane and having a closed contour surrounding the detection chamber.

Certains aspects de l'invention se rapportent à un dispositif de détection de fuite comportant :

  • une cloche de détection de fuite précitée,
  • une pompe à vide raccordée à la chambre de détection pour générer une dépression dans la chambre de détection, et
  • un équipement d'analyse relié à la chambre de détection pour analyser un gaz présent dans la chambre de détection.
Certain aspects of the invention relate to a leak detection device comprising:
  • an aforementioned leak detection bell,
  • a vacuum pump connected to the detection chamber to generate a vacuum in the detection chamber, and
  • analysis equipment connected to the detection chamber to analyze a gas present in the detection chamber.

Certains aspects de l'invention se rapportent à un procédé d'utilisation d'un tel dispositif de détection de fuite ou d'une telle cloche de détection de fuite pour détecter une fuite sur une zone de test d'une membrane d'étanchéité d'une cuve étanche et thermiquement isolante.Certain aspects of the invention relate to a method of using such a leak detection device or such a leak detection bell to detect a leak on a test zone of a waterproofing membrane of a watertight and thermally insulating tank.

Pour cela, selon un premier objet, l'invention fournit un dispositif de détection de fuite pour détecter une fuite sur une zone de test d'une membrane d'étanchéité d'une cuve étanche et thermiquement isolante selon la revendication 1, le dispositif de détection de fuite comportant :

  • une cloche de détection de fuite comprenant un corps principal destiné à être disposé sur la zone de test et un joint d'étanchéité lié au corps principal et configuré pour définir une chambre de détection entre le corps principal et la zone de test, le joint d'étanchéité comportant une lèvre d'étanchéité périphérique configurée pour venir en contact avec la membrane d'étanchéité et présentant un contour fermé entourant la chambre de détection,
  • une pompe à vide raccordée à la chambre de détection pour générer une dépression dans la chambre de détection, et
  • un équipement d'analyse relié à la chambre de détection pour analyser un gaz présent dans la chambre de détection,
dans lequel la lèvre d'étanchéité est configurée pour présenter, au moins dans un état de service dans lequel une dépression est appliquée dans la chambre de détection, une portion de pincement qui vient se pincer entre le corps principal et la membrane d'étanchéité sur au moins une partie de la périphérie de la chambre de détection ou sur toute la périphérie de la chambre de détection.For this, according to a first object, the invention provides a leak detection device for detecting a leak on a test zone of a sealing membrane of a sealed and thermally insulating tank according to claim 1, the device for leak detection comprising:
  • a leak detection bell comprising a main body intended to be placed on the test zone and a seal connected to the main body and configured to define a detection chamber between the main body and the test zone, the seal sealing comprising a peripheral sealing lip configured to come into contact with the sealing membrane and having a closed contour surrounding the detection chamber,
  • a vacuum pump connected to the detection chamber to generate a vacuum in the detection chamber, and
  • analysis equipment connected to the detection chamber to analyze a gas present in the detection chamber,
wherein the sealing lip is configured to present, at least in an operating state in which a vacuum is applied in the detection chamber, a pinching portion which is pinched between the main body and the sealing membrane on at least part of the periphery of the detection chamber or over the entire periphery of the detection chamber.

Selon l'invention, la lèvre d'étanchéité présente une souplesse permettant la formation de ladite portion de pincement par déformation de la lèvre d'étanchéité en direction de la chambre de détection sous l'effet de la dépression dans la chambre de détection.According to the invention, the sealing lip has a flexibility allowing the formation of said pinching portion by deformation of the sealing lip in the direction of the detection chamber under the effect of the depression in the detection chamber.

Selon un mode de réalisation, la chambre de détection de la cloche de détection de fuite présente une zone convexe, par exemple circulaire ou en forme de polygone, destinée à recouvrir une zone de jonction entre quatre tôles métalliques ondulées ou planes.According to one embodiment, the detection chamber of the leak detection bell has a convex zone, for example circular or in the shape of a polygon, intended to cover a junction zone between four corrugated or flat metal sheets.

Selon un mode de réalisation, un cercle géométriquement inscrit dans la zone convexe présente un diamètre supérieur à 68 mm.According to one embodiment, a circle geometrically inscribed in the convex zone has a diameter greater than 68 mm.

Selon un mode de réalisation, la cloche de détection présente une forme allongée le long d'un axe longitudinal, la chambre de détection de la cloche de détection de fuite présentant une zone allongée destinée à recouvrir un bord rectiligne d'une tôle métallique, la zone convexe étant disposée à une extrémité de la zone allongée.According to one embodiment, the detection bell has an elongated shape along a longitudinal axis, the detection chamber of the leak detection bell having an elongated zone intended to cover a straight edge of a metal sheet, the convex zone being disposed at one end of the elongated zone.

Selon un mode de réalisation, la zone convexe est une première zone convexe et la chambre de détection de la cloche de détection de fuite présente une deuxième zone convexe disposée à une extrémité de la zone allongée opposée à la première zone convexe le long de l'axe longitudinal.According to one embodiment, the convex zone is a first convex zone and the detection chamber of the leak detection bell has a second convex zone arranged at one end of the elongated zone opposite to the first convex zone along the longitudinal axis.

Selon un mode de réalisation, la cloche de détection présente une forme allongée le long d'un axe longitudinal, la zone convexe constituant une portion centrale de la chambre de détection de la cloche de détection de fuite, la chambre de détection présentant deux zones allongées s'étendant depuis la zone convexe à l'opposé l'une de l'autre le long de l'axe longitudinal.According to one embodiment, the detection bell has an elongated shape along a longitudinal axis, the convex zone constituting a central portion of the detection chamber of the leak detection bell, the detection chamber having two elongated zones extending from the convex area opposite each other along the longitudinal axis.

Selon un mode de réalisation, la chambre de détection présente une forme circulaire ou polygonale convexe.According to one embodiment, the detection chamber has a circular or convex polygonal shape.

Selon un mode de réalisation, un cercle géométriquement inscrit dans la forme de la chambre de détection présente un diamètre supérieur à 68mm.According to one embodiment, a circle geometrically inscribed in the shape of the detection chamber has a diameter greater than 68 mm.

L'invention fournit aussi un procédé selon la revendication 13 d'utilisation du dispositif de détection de fuite précité sur une zone de test incluant une zone de jonction entre quatre tôles métalliques ondulées ou planes d'une membrane d'étanchéité de cuve, le procédé comportant les étapes de :

  • placer la cloche de détection de fuite sur la zone de test de manière à ce que la lèvre d'étanchéité entre en contact avec la membrane d'étanchéité tout autour de la zone de test et que la zone convexe recouvre ladite zone de jonction,
  • générer une dépression dans la chambre de détection au moyen de la pompe à vide
  • pincer la portion de pincement de la lèvre d'étanchéité entre le corps principal et la membrane d'étanchéité sur au moins une partie de la périphérie de la chambre de détection
  • conduire les gaz présents dans la chambre de détection vers l'équipement d'analyse, et
  • analyser au moyen de l'équipement d'analyse les gaz venant de la chambre de détection pour produire un signal de mesure représentant une quantité d'au moins un gaz présent dans la chambre de détection.
The invention also provides a method according to claim 13 for using the aforementioned leak detection device on a test zone including a junction zone between four corrugated or flat metal sheets of a tank sealing membrane, the method comprising the steps of:
  • place the leak detection bell on the test area so that the sealing lip comes into contact with the sealing membrane all around the test area and that the convex area covers said junction area,
  • generate a vacuum in the detection chamber by means of the vacuum pump
  • pinch the pinch portion of the sealing lip between the main body and the sealing membrane over at least a portion of the periphery of the sensing chamber
  • lead the gases present in the detection chamber to the analysis equipment, and
  • analyzing by means of the analysis equipment the gases coming from the detection chamber to produce a measurement signal representing a quantity of at least one gas present in the detection chamber.

Selon un mode de réalisation, la cloche de détection comporte en outre au moins une poignée de manutention disposée sur une surface supérieure de la cloche de détection tournée à l'opposé de la lèvre d'étanchéité.According to one embodiment, the detection bell further comprises at least one handling handle arranged on an upper surface of the detection bell facing away from the sealing lip.

Selon un mode de réalisation, la cloche de détection comporte deux poignées de manutention disposée sur la surface supérieure à proximité des deux extrémités longitudinales de la cloche de détection.According to one embodiment, the detection bell comprises two handling handles arranged on the upper surface close to the two longitudinal ends of the detection bell.

Selon un mode de réalisation, la ou chaque poignée de manutention est disposée sur une surface supérieure de la cloche de détection tournée à l'opposé de la lèvre d'étanchéité.According to one embodiment, the or each handling handle is arranged on an upper surface of the detection bell facing away from the sealing lip.

Selon un mode de réalisation, l'équipement d'analyse comporte un spectromètre de masse.According to one embodiment, the analysis equipment includes a mass spectrometer.

Selon d'autres modes de réalisation avantageux, une telle cloche peut présenter une ou plusieurs des caractéristiques suivantes.According to other advantageous embodiments, such a bell may have one or more of the following characteristics.

Selon un mode de réalisation, la cloche de détection comprend :

  • un moyen mécanique de pression porté par le corps principal et comportant au moins un élément de pression configuré pour exercer sur une portion de la lèvre d'étanchéité une pression dirigée vers la membrane lorsque le corps principal est disposé sur la zone de test.
According to one embodiment, the detection bell comprises:
  • a mechanical pressure means carried by the main body and comprising at least one pressure element configured to exert on a portion of the sealing lip a pressure directed towards the membrane when the main body is positioned on the test area.

Grâce à ces caractéristiques, la cloche de détection peut être placée rapidement sur une zone de test afin que le joint d'étanchéité puisse former une chambre de détection sur toute la zone de test. De plus, le moyen mécanique de pression permet de presser la lèvre d'étanchéité sur une ou plusieurs portions, notamment là où il se présente un risque que le joint d'étanchéité se décolle de la membrane d'étanchéité, afin de fiabiliser la détection d'une éventuelle fuite par la cloche de détection.Thanks to these features, the detection bell can be quickly placed on a test area so that the gasket can form a detection chamber over the entire test area. In addition, the mechanical pressure means makes it possible to press the sealing lip on one or more portions, in particular where there is a risk that the seal will detach from the sealing membrane, in order to make the detection more reliable. of a possible leak through the detection bell.

Avantageusement, la cloche de détection est apte à détecter un gaz traceur ayant été injecté pour les besoins du test, par exemple de l'hélium, ou un gaz de l'air ambiant. Selon une possibilité offerte par l'invention, ce gaz traceur n'est pas nécessairement injecté dans la zone dont test l'étanchéité, il peut être dans la zone par une autre manière. Par « air ambiant » on entend une phase gazeuse présentant une composition proche de l'air sec ambiant, c'est-à-dire comportant environ 78% de diazote, 21 % de dioxygène, 0.9 % d'argon ainsi que des gaz rares et des composés organiques volatiles susceptibles d'être émis par une colle utilisée dans la barrière thermiquement isolante ou provenant des matières solides isolantes.Advantageously, the detection bell is capable of detecting a tracer gas having been injected for the purposes of the test, for example helium, or a gas from the ambient air. According to a possibility offered by the invention, this tracer gas is not necessarily injected into the zone whose sealing test, it can be in the zone in another way. By “ambient air” is meant a gaseous phase having a composition close to ambient dry air, that is to say comprising approximately 78% nitrogen, 21% oxygen, 0.9% argon as well as rare gases and volatile organic compounds likely to be emitted by an adhesive used in the thermally insulating barrier or originating from the solid insulating materials.

En outre, grâce à la cloche de détection de fuite selon l'invention, on est dorénavant capable d'obtenir, sans difficulté, une pression absolue inférieure à 100 Pa dans la chambre de détection, par exemple de l'ordre de 50 à 60 Pa (0,5-0,6 mbar).In addition, thanks to the leak detection bell according to the invention, it is now possible to obtain, without difficulty, an absolute pressure of less than 100 Pa in the detection chamber, for example of the order of 50 to 60 Pa (0.5-0.6 mbar).

Selon un mode de réalisation, l'élément de pression est un élément déformable élastiquement qui exerce une pression sur la portion de la lèvre d'étanchéité par déformation élastique.According to one embodiment, the pressure element is an elastically deformable element which exerts pressure on the portion of the sealing lip by elastic deformation.

Ainsi, l'élasticité de l'élément de pression permet lors de sa déformation élastique d'exercer un effort de rappel sur la lèvre d'étanchéité vers la membrane d'étanchéité.Thus, the elasticity of the pressure element makes it possible, during its elastic deformation, to exert a return force on the sealing lip towards the sealing membrane.

Selon un mode de réalisation, l'élément de pression est orienté perpendiculairement au contour de la lèvre d'étanchéité périphérique.According to one embodiment, the pressure element is oriented perpendicular to the contour of the peripheral sealing lip.

Selon un mode de réalisation, la lèvre d'étanchéité présente un état de service, lorsqu'une dépression est appliquée dans la chambre de détection, et une portion de pincement de la lèvre d'étanchéité est maintenue entre le corps principal et la membrane d'étanchéité sur au moins une partie de la périphérie de la chambre de détection, avantageusement sur toute la périphérie de ladite chambre.According to one embodiment, the sealing lip has a service state, when a vacuum is applied in the detection chamber, and a pinching portion of the sealing lip is maintained between the main body and the membrane of sealing over at least part of the periphery of the detection chamber, advantageously over the entire periphery of said chamber.

Selon un mode de réalisation, la cloche de détection de fuite présente une forme allongée d'une longueur supérieure ou égale à 0,5 m, préférentiellement supérieure ou égale à 1 m, de façon plus préférentielle supérieure ou égale à 2 m. De plus, la cloche de détection de fuite peut présenter une largeur comprise entre 10 et 20 centimètre (cm), de préférence entre 14 cm et 16 cm.According to one embodiment, the leak detection bell has an elongated shape with a length greater than or equal to 0.5 m, preferably greater than or equal to 1 m, more preferably greater than or equal to 2 m. In addition, the leak detection bell may have a width of between 10 and 20 centimeters (cm), preferably between 14 cm and 16 cm.

Concernant le poids d'une telle cloche de détection, il pourra être compris entre 3 kilos et 25 kilos, préférentiellement entre 5 et 10 kilos, en fonction en particulier des matériaux utilisés, de sa longueur et de sa largeur.Regarding the weight of such a detection bell, it may be between 3 kilos and 25 kilos, preferably between 5 and 10 kilos, depending in particular on the materials used, its length and its width.

Selon un mode de réalisation, le moyen mécanique de pression comporte une pluralité d'éléments de pression configurés pour exercer une pression sur une pluralité de portions de la lèvre d'étanchéité, des portions étant situées aux deux extrémités de la lèvre d'étanchéité dans une direction longitudinale.According to one embodiment, the mechanical pressure means comprises a plurality of pressure elements configured to exert pressure on a plurality of portions of the sealing lip, portions being located at the two ends of the sealing lip in a longitudinal direction.

Selon un mode d'exécution de l'invention, des portions de la lèvre d'étanchéité pressées par le moyen mécanique de pression sont situées aux deux extrémités de la lèvre d'étanchéité dans une direction longitudinale, soit aux deux extrémités de la cloche compte tenu que cette dernière présente une forme générale longitudinale.According to one embodiment of the invention, portions of the sealing lip pressed by the mechanical pressure means are located at both ends of the sealing lip in a longitudinal direction, either at the two ends of the bell given that the latter has a generally longitudinal shape.

Ainsi, le moyen mécanique de pression applique une pression sur différentes zones où il y a un risque de décollement du joint, à savoir les extrémités du joint d'étanchéité.Thus, the mechanical pressure means applies pressure to different areas where there is a risk of the seal detaching, namely the ends of the seal.

Selon un mode de réalisation, la lèvre d'étanchéité comporte au moins une échancrure présentant une forme correspondant à celle d'une ondulation de la membrane, l'échancrure étant destinée à enjamber l'ondulation.According to one embodiment, the sealing lip comprises at least one indentation having a shape corresponding to that of an undulation of the membrane, the indentation being intended to span the undulation.

Selon un mode de réalisation, la lèvre d'étanchéité comporte au moins deux échancrures, par exemple trois échancrures.According to one embodiment, the sealing lip comprises at least two notches, for example three notches.

Grâce à ces caractéristiques, il est possible de placer la cloche de détection sur une membrane d'étanchéité comprenant des tôles ondulées, le ou les échancrures permettant à la cloche d'enjamber les ondulations.Thanks to these characteristics, it is possible to place the detection bell on a sealing membrane comprising corrugated sheets, the indentation(s) allowing the bell to span the corrugations.

La cloche de détection de fuites est ainsi apte, lorsqu'elle utilisée sur une zone de membrane comportant des ondes, à tester les zones de soudure présentes sur une pluralité d'ondes, par exemple au moins trois (3) ondes et jusqu'à près d'une dizaine d'ondes. Il pourra également être envisagé d'associer plusieurs cloches de détection les unes à côté des autres, ou les unes à la suite des autres, afin de former une longueur de zone de test plus grande. Selon un mode de réalisation, une seule pompe à vide peut être utilisée pour générer le vide requis dans des cloches de détection de fuites associées les unes aux autres.The leak detection bell is thus suitable, when it is used on a zone of membrane comprising waves, to test the weld zones present on a plurality of waves, for example at least three (3) waves and up to nearly a dozen waves. It may also be envisaged to associate several detection bells next to each other, or one after the other, in order to form a longer test zone length. According to one embodiment, a single vacuum pump can be used to generate the required vacuum in leak detection bells associated with each other.

Selon un mode de réalisation, une portion de la lèvre d'étanchéité pressée par le moyen mécanique de pression est située à une base de l'échancrure.According to one embodiment, a portion of the sealing lip pressed by the mechanical pressure means is located at a base of the notch.

Grâce à cette caractéristique, il est possible de placer la cloche de détection sur une membrane d'étanchéité comprenant des tôles ondulées, le ou les échancrures permettant à la cloche d'enjamber les ondulations.Thanks to this feature, it is possible to place the detection bell on a sealing membrane comprising corrugated sheets, the indentation(s) allowing the bell to span the corrugations.

Ainsi, le moyen mécanique de pression applique une pression sur une zone où il y a des risques de décollement du joint d'étanchéité dus au changement de pente de l'échancrure.Thus, the mechanical pressure means applies pressure to an area where there is a risk of the seal detaching due to the change in slope of the notch.

Selon un mode de réalisation, le moyen mécanique de pression comporte une pluralité d'éléments de pression configurés pour exercer une pression sur une pluralité de portions de la lèvre d'étanchéité, des portions étant situées aux bases de l'échancrure ou des échancrures.According to one embodiment, the mechanical pressure means comprises a plurality of pressure elements configured to exert pressure on a plurality of portions of the sealing lip, portions being located at the bases of the notch or notches.

Ainsi, le moyen mécanique de pression applique une pression sur différentes zones où il y a un risque de décollement du joint, à savoir la base de ou des échancrures.Thus, the mechanical pressure means applies pressure to different areas where there is a risk of the seal detaching, namely the base of the indentations.

Selon un mode de réalisation, la portion de la lèvre d'étanchéité est située sur un sommet de l'échancrure.According to one embodiment, the portion of the sealing lip is located on a top of the notch.

Selon un mode d'exécution de l'invention, toutes les portions de la lèvre d'étanchéité situées aux bases de l'échancrure sont pressées par la pluralité d'éléments de pression du moyen mécanique.According to one embodiment of the invention, all the portions of the sealing lip located at the bases of the indentation are pressed by the plurality of pressure elements of the mechanical means.

Selon un mode de réalisation, au moins un des, une partie des ou les éléments de pression comportent une lame courbée dont au moins une des extrémités vient en butée sur la base d'une échancrureAccording to one embodiment, at least one of, part of or the pressure elements comprise a curved blade, at least one of the ends of which comes into abutment on the base of an indentation

Avantageusement, au moins un des, une partie des ou les éléments de pression comportent une lame courbée dont les deux extrémités viennent en butée sur la base de deux échancrures contiguës.Advantageously, at least one of, part of or the pressure elements comprise a curved blade whose two ends come into abutment on the base of two contiguous notches.

Grâce à cette caractéristique, le positionnement de la cloche de détection de fuite est rendu plus aisé car la lame courbée va permettre le placement adéquat en pression des échancrures de la lèvre d'étanchéité sur les deux ondes contiguës de la membrane, quel que soient les éventuelles légères variations de la distance entre ces deux ondes contiguës ou le positionnement approximatif de la cloche de détection de fuite sur la membrane à ondes par un ou plusieurs opérateurs.Thanks to this characteristic, the positioning of the leak detection bell is made easier because the curved blade will allow the adequate placement under pressure of the indentations of the sealing lip on the two contiguous waves of the membrane, whatever the possible slight variations in the distance between these two contiguous waves or the approximate positioning of the leak detection bell on the wave membrane by one or more operators.

Selon un mode de réalisation, un élément support s'étend sur toute la longueur du corps principal au-dessus de celui-ci et est fixé au corps principal.According to one embodiment, a support element extends over the entire length of the main body above it and is fixed to the main body.

Selon un mode de réalisation, les lames courbées sont réparties sur la lèvre d'étanchéité et sont fixées par des moyens de fixation à l'élément support.According to one embodiment, the curved blades are distributed over the sealing lip and are fixed by fixing means to the support element.

Selon un mode de réalisation, les lames courbées sont déformables élastiquement de manière à, lorsqu'elles sont déformées, exercer un effort de retour élastique sur la lèvre d'étanchéité.According to one embodiment, the curved blades are elastically deformable so as to, when they are deformed, exert an elastic return force on the sealing lip.

Selon un mode de réalisation, les moyens de fixation comportent une pluralité de pions, les pions comprenant chacun une tige montée mobile sur un corps, la tige comportant une extrémité en appui contre l'une des lames courbées, le corps étant fixé à l'élément de support, et comprenant également un ressort reliant la tige au corps, le ressort agissant entre le corps et la tige afin de positionner l'extrémité de la tige en appui contre la lame courbée et le ressort étant configuré pour exercer une force de rappel sur la lame courbée de sorte que la lame courbée vienne plaquer la lèvre d'étanchéité contre le pied d'une ondulation.According to one embodiment, the fixing means comprise a plurality of pins, the pins each comprising a rod mounted to move on a body, the rod comprising one end resting against one of the curved blades, the body being fixed to the support member, and also comprising a spring connecting the rod to the body, the spring acting between the body and the rod to position the end of the rod to bear against the curved blade and the spring being configured to exert a restoring force on the curved blade so that the curved blade presses the sealing lip against the foot of an undulation.

Selon un mode de réalisation, le moyen mécanique de pression comprend une pluralité d'éléments de pression d'extrémité, les éléments de pression d'extrémité étant situés aux deux extrémités de la lèvre d'étanchéité dans une direction longitudinale, soit aux deux extrémités de la cloche étant donné que cette dernière présente une forme longitudinale.According to one embodiment, the mechanical pressure means comprises a plurality of end pressure elements, the end pressure elements being located at both ends of the sealing lip in a longitudinal direction, i.e. at both ends of the bell since the latter has a longitudinal shape.

Selon un mode de réalisation, au moins un ou les éléments de pression d'extrémité comprennent un pion d'extrémité, le pion d'extrémité comprenant une tige montée mobile sur un corps, un élément d'appui allongé étant fixé à une extrémité de la tige, l'élément d'appui allongé venant en appui contre la lèvre d'étanchéité, et le corps étant fixé à l'élément de support, le pion d'extrémité comprenant également un ressort reliant la tige au corps, le ressort agissant entre le corps et la tige afin de positionner l'élément d'appui allongé contre la lèvre d'étanchéité, le ressort étant configuré pour exercer une force de rappel sur l'élément d'appui allongé de sorte que l'élément d'appui allongé vienne plaquer la lèvre d'étanchéité contre la zone à tester.According to one embodiment, at least one or more end pressure elements comprise an end pin, the end pin comprising a rod movably mounted on a body, an elongated support element being fixed to one end of the rod, the elongated support element bearing against the sealing lip, and the body being fixed to the support element, the end pin also comprising a spring connecting the rod to the body, the spring acting between the body and the stem to position the elongated bearing member against the sealing lip, the spring being configured to exert a biasing force on the elongated bearing member such that the bearing member elongated presses the sealing lip against the area to be tested.

Selon un mode de réalisation, la deuxième extrémité est équipée d'un élément d'appui allongé, l'élément d'appui allongé étant configuré pour transmettre l'effort de retour élastique sur une zone de la lèvre d'étanchéité correspondant à une longueur de l'élément d'appui allongé.According to one embodiment, the second end is equipped with an elongated bearing element, the elongated bearing element being configured to transmit the springback force over a zone of the sealing lip corresponding to a length of the elongated support element.

Selon un mode de réalisation, la deuxième extrémité d'un premier pion d'extrémité et la deuxième extrémité d'un deuxième pion d'extrémité adjacent au premier pion d'extrémité sont fixées l'une à l'autre à l'aide d'un élément d'appui allongé.According to one embodiment, the second end of a first end pin and the second end of a second end pin adjacent to the first end pin are fixed to each other using an elongated support element.

Selon un mode de réalisation, au moins un ou les éléments de pression d'extrémité comprennent une pluralité d'éléments de réglage formant une ligne d'éléments, l'élément de réglage comprenant une tige s'étendant en direction de la lèvre d'étanchéité et une extrémité réglable dans une direction longitudinale de la tige de sorte à venir en contact avec la lèvre d'étanchéité après réglage.According to one embodiment, at least one or more end pressure elements comprise a plurality of adjustment elements forming a line of elements, the adjustment element comprising a rod extending in the direction of the lip of sealing and an adjustable end in a longitudinal direction of the rod so as to come into contact with the sealing lip after adjustment.

Selon un mode de réalisation, l'élément de pression comporte une lame courbée comprenant à une de ses extrémités en contact avec la lèvre d'étanchéité un manchon cylindrique.According to one embodiment, the pressure element comprises a curved blade comprising at one of its ends in contact with the sealing lip a cylindrical sleeve.

Ainsi, le manchon cylindrique permet d'appliquer uniformément la pression du moyen mécanique de pression sur une partie de la lèvre d'étanchéité.Thus, the cylindrical sleeve makes it possible to uniformly apply the pressure of the mechanical pressure means on a part of the sealing lip.

Selon un mode de réalisation, le joint d'étanchéité comprend une enveloppe qui recouvre au moins partiellement le corps principal et qui est fixée au corps principal, la lèvre d'étanchéité périphérique étant liée à l'enveloppe de manière à la prolonger et étant recourbée à l'opposé du corps principal.According to one embodiment, the sealing gasket comprises an envelope which at least partially covers the main body and which is fixed to the main body, the peripheral sealing lip being linked to the envelope so as to extend it and being curved opposite the main body.

Selon un mode de réalisation, le manchon cylindrique comprend une direction de longueur, la direction de longueur du manchon cylindrique étant sensiblement orthogonale à l'enveloppe de manière à ce que le manchon cylindrique s'étende de l'enveloppe à une extrémité de la lèvre d'étanchéité.According to one embodiment, the cylindrical sleeve comprises a direction of length, the direction of length of the cylindrical sleeve being substantially orthogonal to the casing so that the cylindrical sleeve extends from the casing to one end of the lip sealing.

Selon un mode de réalisation, la lèvre d'étanchéité comprend une partie recourbée sensiblement orthogonale à l'enveloppe, la partie recourbée ayant une dimension en section transversale supérieure ou égale à 1 cm, de préférence supérieure ou égale à 1,5 cm, de façon plus préférentielle supérieure ou égale à 2 cm.According to one embodiment, the sealing lip comprises a curved part substantially orthogonal to the casing, the curved part having a cross-sectional dimension greater than or equal to 1 cm, preferably greater than or equal to 1.5 cm, of more preferably greater than or equal to 2 cm.

Selon un mode de réalisation, le joint d'étanchéité est réalisé dans un matériau élastomère présentant une dureté comprise entre 20 et 50 shore A.According to one embodiment, the seal is made of an elastomeric material having a hardness of between 20 and 50 shore A.

Grâce à ces caractéristiques, le joint d'étanchéité est composé d'un matériau suffisamment souple pour être déformé par le moyen mécanique de pression.Thanks to these characteristics, the seal is made of a material that is flexible enough to be deformed by the mechanical means of pressure.

Selon un mode de réalisation, le matériau élastomère du joint d'étanchéité est choisi parmi le polyuréthane élastomère et le caoutchouc éthylène-propylène-diène monomère (EPDM). Le matériau élastomère du joint d'étanchéité peut également être en silicone, en nitrile ou en Viton ®.According to one embodiment, the elastomeric material of the seal is chosen from elastomeric polyurethane and ethylene-propylene-diene rubber monomer (EPDM). The elastomer material of the seal can also be silicone, nitrile or Viton ® .

Selon un mode de réalisation, le corps principal comporte un noyau rigide, et le joint d'étanchéité comporte une enveloppe appliquée hermétiquement contre une paroi périphérique du noyau rigide.According to one embodiment, the main body comprises a rigid core, and the seal comprises an envelope applied hermetically against a peripheral wall of the rigid core.

Selon un mode de réalisation, le noyau rigide comporte un évidement sur une surface inférieure destinée à être tournée vers la zone de test.According to one embodiment, the rigid core comprises a recess on a lower surface intended to be turned towards the test area.

Selon un mode de réalisation, le noyau rigide comporte un canal reliant l'évidement à une surface supérieure du noyau rigide pour connecter une pompe à vide.According to one embodiment, the rigid core has a channel connecting the recess to an upper surface of the rigid core to connect a vacuum pump.

Selon un mode de réalisation, la cloche de détection de fuite est orientée sur la zone de test de manière qu'une longueur de la cloche de détection de fuite soit superposée avec la zone de test.According to one embodiment, the leak detection bell is oriented over the test area so that a length of the leak detection bell is superimposed with the test area.

Selon un mode de réalisation, la zone de test est une partie d'un cordon de soudure de la membrane d'étanchéité.According to one embodiment, the test zone is part of a weld bead of the sealing membrane.

Ainsi, la cloche de détection de fuite permet de vérifier s'il n'y a pas de défaut sur le cordon de soudure qui pourrait engendrer une fuite dans la membrane d'étanchéité.Thus, the leak detection bell makes it possible to check whether there is any defect on the weld bead which could cause a leak in the waterproofing membrane.

Selon un mode de réalisation, la zone de test se situe sur une membrane d'étanchéité ondulée.According to one embodiment, the test area is located on a corrugated sealing membrane.

Selon un mode de réalisation, la lèvre d'étanchéité périphérique est conformée pour s'adapter à la géométrie de ladite au moins une ondulation.According to one embodiment, the peripheral sealing lip is shaped to adapt to the geometry of said at least one undulation.

Selon un mode de réalisation, la portion du cordon de soudure est traversée par au moins deux ondulations, par exemple trois ondulations, parallèles de la membrane et la lèvre d'étanchéité périphérique est conformée pour s'adapter à la géométrie desdites ondulations.According to one embodiment, the portion of the weld bead is crossed by at least two undulations, for example three undulations, parallel to the membrane and the peripheral sealing lip is shaped to adapt to the geometry of said undulations.

Selon un mode de réalisation, la lèvre d'étanchéité périphérique comporte au moins deux échancrures présentant une forme correspondant à celle d'une ondulation de la membrane faisant saillie vers l'intérieur de la cuve, lesdites échancrures étant destinées à enjamber ladite ondulation.According to one embodiment, the peripheral sealing lip comprises at least two indentations having a shape corresponding to that of an undulation of the membrane projecting towards the inside of the tank, said indentations being intended to span said undulation.

Selon un mode de réalisation, au moins une ondulation de la membrane fait saillie vers l'intérieur de la cuve, la cloche de détection étant disposée contre la membrane de manière à ce que les échancrures enjambent l'ondulation.According to one embodiment, at least one corrugation of the membrane protrudes towards the inside of the tank, the detection bell being placed against the membrane so that the indentations span the corrugation.

Selon un mode de réalisation, la lèvre d'étanchéité périphérique comporte au moins deux zones en saillie présentant une forme correspondant à celle d'une ondulation de la membrane faisant saillie vers l'extérieur de la cuve.According to one embodiment, the peripheral sealing lip comprises at least two projecting zones having a shape corresponding to that of an undulation of the membrane projecting towards the outside of the tank.

Selon un mode de réalisation, la cloche de détection est disposée contre la membrane de manière à ce que les zones en saillie s'insèrent dans l'ondulation.According to one embodiment, the detection bell is placed against the membrane so that the projecting zones fit into the undulation.

Selon un mode de réalisation, l'on met en dépression la chambre de détection jusqu'à une valeur de pression absolue comprise entre 10 et 1000 Pa, de préférence inférieure à 100 Pa absolu.According to one embodiment, the detection chamber is placed under depression to an absolute pressure value of between 10 and 1000 Pa, preferably less than 100 Pa absolute.

Selon un mode de réalisation, l'on analyse la phase gazeuse pendant une durée supérieure ou égale à 5 secondes.According to one embodiment, the gaseous phase is analyzed for a period greater than or equal to 5 seconds.

Selon un mode de réalisation, l'on compare la variable représentative d'une quantité de gaz dans ladite phase gazeuse à un seuil et l'on détermine que l'étanchéité de la portion du cordon de soudure est défectueuse lorsque la variable représentative est supérieure audit seuil.According to one embodiment, the variable representative of a quantity of gas in said gaseous phase is compared with a threshold and it is determined that the tightness of the portion of the weld bead is defective when the representative variable is greater said threshold.

Selon des modes de réalisation, l'équipement d'analyse est configuré pour détecter un gaz traceur ou pour détecter un composant de l'air ambiant.According to embodiments, the analysis equipment is configured to detect a tracer gas or to detect a component of the ambient air.

Brève description des dessinsBrief description of the drawings

L'invention sera mieux comprise, et d'autres buts, détails, caractéristiques et avantages de celle-ci apparaîtront plus clairement au cours de la description suivante de plusieurs modes de réalisation particuliers de l'invention, donnés uniquement à titre illustratif et non limitatif, en référence aux dessins annexés.

  • [Fig.1] est une vue schématique d'un dispositif de détection de fuite selon un premier mode de réalisation.
  • [Fig.2] est une vue en coupe transversale selon le plan II-II de la cloche de détection du dispositif de détection de fuite de la figure 1.
  • [Fig.3] est une vue en perspective d'un joint d'étanchéité selon un premier mode de réalisation.
  • [Fig.4] est une vue schématique d'une variante d'un dispositif de détection de fuite dans laquelle la cloche de détection est équipée d'un système de serrage.
  • [Fig.5] est une vue en perspective d'un joint d'étanchéité selon un deuxième mode de réalisation.
  • [Fig.6] illustre schématiquement le positionnement de la cloche de détection en regard d'une portion d'un cordon de soudure assurant l'étanchéité entre deux tôles métalliques ondulées adjacentes d'une membrane.
  • [Fig.7] est une vue schématique d'un dispositif de détection de fuite selon un deuxième mode de réalisation.
  • [Fig.8] est une vue en perspective d'une cloche de détection de fuite selon un troisième mode de réalisation.
  • [Fig.9] est une vue schématique en coupe transversale de la cloche de détection de la figure 8, avant mise en dépression de la chambre de détection.
  • [Fig.10] est une vue schématique en coupe transversale de la cloche de détection de la figure 8, après mise en dépression de la chambre de détection.
  • [Fig.11] est une illustration schématique d'une structure multicouche d'une paroi d'une cuve à membranes.
  • [Fig.12] est une vue schématique partielle d'une cuve étanche et thermiquement isolante illustrant des dispositifs d'injection de gaz traceur positionnés au travers d'une membrane de la paroi de fond de la cuve.
  • [Fig.13] est une vue en perspective d'une cloche de détection de fuite selon un quatrième mode de réalisation.
  • [Fig.14] est une vue agrandie du détail XIV de la figure 13 illustrant un élément de pression de la cloche de détection de fuite.
  • [Fig.15] représente une vue agrandie du détail XV de la figure 13 illustrant une première extrémité de la cloche de détection de fuite.
  • [Fig.16] représente une vue agrandie du détail XVI de la figure 13 illustrant une deuxième extrémité de la cloche de détection de fuite.
  • [Fig.17] représente une vue agrandie du détail XVI de la figure 13 selon un autre angle de vue.
  • [FIG. 18] est une vue de dessus d'une membrane d'étanchéité illustrant schématiquement une cloche de détection positionnée pour tester une jonction entre quatre tôles rectangulaires.
  • [FIG. 19] est une vue analogue à la figure 18 illustrant une autre géométrie de la cloche de détection positionnée pour tester une jonction entre quatre tôles rectangulaires.
  • [FIG. 20] est une vue analogue à la figure 18 illustrant encore une autre géométrie de la cloche de détection positionnée pour tester une jonction entre quatre tôles rectangulaires.
  • [FIG. 21] est une vue de dessus de la cloche de détection de fuite de la figure 13, illustrant également un dispositif de visée optique.
  • [FIG. 22] est une vue schématique fonctionnelle d'un dispositif de détection de fuite employant la cloche de détection de fuite de la figure 13.
  • [FIG. 23] est un diagramme illustrant un procédé d'activation pouvant être mis en oeuvre dans le dispositif de détection de fuite de la figure 22.
  • [FIG. 24] est un diagramme illustrant un procédé de désactivation pouvant être mis en œuvre dans le dispositif de détection de fuite de la figure 22.
  • [FIG. 25] est une vue schématique fonctionnelle d'une vanne à trois voies pouvant être employée dans le dispositif de détection de fuite de la figure 22.
The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely by way of illustration and not of limitation. , with reference to the accompanying drawings.
  • [ Fig.1 ] is a schematic view of a leak detection device according to a first embodiment.
  • [ Fig.2 ] is a cross-sectional view along the plane II-II of the detection bell of the leak detection device of the figure 1 .
  • [ Fig.3 ] is a perspective view of a seal according to a first embodiment.
  • [ Fig.4 ] is a schematic view of a variant of a leak detection device in which the detection bell is equipped with a clamping system.
  • [ Fig.5 ] is a perspective view of a seal according to a second embodiment.
  • [ Fig.6 ] schematically illustrates the positioning of the detection bell opposite a portion of a weld bead ensuring the seal between two adjacent corrugated metal sheets of a membrane.
  • [ Fig.7 ] is a schematic view of a leak detection device according to a second embodiment.
  • [ Fig.8 ] is a perspective view of a leak detection bell according to a third embodiment.
  • [ Fig.9 ] is a cross-sectional schematic view of the detection bell of the figure 8 , before depressurization of the detection chamber.
  • [ Fig.10 ] is a cross-sectional schematic view of the detection bell of the figure 8 , after depressurization of the detection chamber.
  • [ Fig.11 ] is a schematic illustration of a multilayer structure of a membrane tank wall.
  • [ Fig.12 ] is a partial schematic view of a sealed and thermally insulating tank illustrating tracer gas injection devices positioned through a membrane of the bottom wall of the tank.
  • [ Fig.13 ] is a perspective view of a leak detection bell according to a fourth embodiment.
  • [ Fig.14 ] is an enlarged view of detail XIV of the figure 13 illustrating a pressure element of the leak detection bell.
  • [ Fig.15 ] represents an enlarged view of detail XV of the figure 13 illustrating a first end of the leak detection bell.
  • [ Fig.16 ] represents an enlarged view of detail XVI of the figure 13 illustrating a second end of the leak detection bell.
  • [ Fig.17 ] represents an enlarged view of detail XVI of the figure 13 from another angle.
  • [ FIG. 18 ] is a top view of a waterproofing membrane schematically illustrating a detection bell positioned to test a junction between four rectangular sheets.
  • [ FIG. 19 ] is a view analogous to the figure 18 illustrating another geometry of the detection bell positioned to test a junction between four rectangular sheets.
  • [ FIG. 20 ] is a view analogous to the figure 18 illustrating yet another geometry of the detection bell positioned to test a junction between four rectangular sheets.
  • [ FIG. 21 ] is a top view of the leak detection bell of the figure 13 , also illustrating an optical sighting device.
  • [ FIG. 22 ] is a functional schematic view of a leak detection device employing the leak detection bell of the figure 13 .
  • [ FIG. 23 ] is a diagram illustrating an activation method that can be implemented in the leak detection device of the figure 22 .
  • [ FIG. 24 ] is a diagram illustrating a deactivation method that can be implemented in the leak detection device of the figure 22 .
  • [ FIG. 25 ] is a functional schematic view of a three-way valve which may be employed in the leak detection device of the figure 22 .

Description des modes de réalisationDescription of embodiments

On va décrire ci-dessous un dispositif de détection de fuite qui peut être utilisé pour détecter des fuites dans différents assemblages étanches, par exemple un assemblage soudé. Dans les exemples ci-dessous, l'assemblage soudé est une membrane d'étanchéité pour une cuve de fluide.A description will be given below of a leak detection device which can be used to detect leaks in various sealed assemblies, for example a welded assembly. In the examples below, the welded assembly is a sealing membrane for a fluid tank.

Pendant l'étape du test d'étanchéité permettant de vérifier l'étanchéité des cordons de soudure d'une membrane 5, 8, on utilise un dispositif de détection de fuite 54, tel que représenté sur la figure 1.During the stage of the sealing test making it possible to check the sealing of the weld beads of a membrane 5, 8, a leak detection device 54 is used, as represented on the figure 1 .

Le dispositif de détection de fuite 54 comporte une cloche de détection 55 qui est destinée à être disposée contre la face interne de la membrane 5, 8 en regard d'une portion du cordon de soudure à tester.The leak detection device 54 comprises a detection bell 55 which is intended to be placed against the internal face of the membrane 5, 8 facing a portion of the weld bead to be tested.

La cloche de détection 55 présente une forme allongée et présente une longueur comprise entre 0,5 et 4 m, par exemple de l'ordre de 1 m. La longueur de la cloche de détection 55 est avantageusement la plus grande possible de manière à vérifier l'étanchéité d'une zone plus importante au cours d'un seul et unique test. Néanmoins, le choix de cette longueur de la cloche pourra être adaptée en fonction d'une part des dimensions de la membrane 5, 8 à tester et d'autre part en vue de sa manœuvrabilité par un minimum d'opérateur(s), de préférence par un seul opérateur. Une forme allongée est particulièrement adaptée à tester un assemblage de tôles métalliques rectangulaires, dans lequel les cordons de soudure suivent essentiellement les bords rectilignes des tôles.The detection bell 55 has an elongated shape and has a length of between 0.5 and 4 m, for example of the order of 1 m. The length of the detection bell 55 is advantageously as long as possible so as to check the tightness of a larger zone during a single and unique test. Nevertheless, the choice of this length of the bell can be adapted according on the one hand to the dimensions of the membrane 5, 8 to be tested and on the other hand with a view to its maneuverability by a minimum of operator(s), preferably by a single operator. An elongated shape is particularly suitable for testing an assembly of rectangular metal sheets, in which the weld beads essentially follow the straight edges of the sheets.

Comme représenté sur la figure 2, la cloche de détection 55 comporte un corps principal 100 rigide et un joint d'étanchéité 60 souple qui sont fixés l'un à l'autre et qui sont agencés pour définir avec la membrane 5,8 à tester une chambre de détection 61 étanche, disposée en regard de la portion du cordon de soudure 62 à tester.As shown on the figure 2 , the detection bell 55 comprises a rigid main body 100 and a flexible seal 60 which are fixed to one another and which are arranged to define with the membrane 5.8 to be tested a sealed detection chamber 61 , arranged opposite the portion of the weld bead 62 to be tested.

En revenant à la figure 1, on observe que le dispositif de détection de fuite 54 comporte également un équipement d'analyse 56 qui est raccordé à la chambre de détection 61 et permet de détecter un gaz prédéfini, par exemple un gaz traceur ou un gaz de l'air ambiant présent de l'autre côté de l'assemblage soudé à tester. Dès lors que l'équipement d'analyse 56 détecte le gaz prédéfini dans une quantité supérieure à un seuil, il peut être conclu à un défaut d'étanchéité de la portion du cordon de soudure 62 testée. Selon un mode de réalisation, l'équipement d'analyse 56 est un spectromètre de masse.Coming back to the figure 1 , it is observed that the leak detection device 54 also comprises analysis equipment 56 which is connected to the detection chamber 61 and makes it possible to detect a predefined gas, for example a tracer gas or an ambient air gas present on the other side of the weldment to be tested. As soon as the analysis equipment 56 detects the predefined gas in a quantity greater than a threshold, it can be concluded that there is a leak in the portion of the weld bead 62 tested. According to one embodiment, the analysis equipment 56 is a mass spectrometer.

Le dispositif de détection de fuite 54 comporte également une pompe à vide 57 qui est associée audit équipement d'analyse 56. La pompe à vide 57 est raccordée, d'une part, à la chambre de détection de la cloche de détection 55 de manière à permettre une mise en dépression de la chambre de détection et, d'autre part, à l'équipement d'analyse 56 de manière à conduire le gaz contenu dans la chambre de détection 61 vers l'équipement d'analyse 56.The leak detection device 54 also comprises a vacuum pump 57 which is associated with said analysis equipment 56. The vacuum pump 57 is connected, on the one hand, to the detection chamber of the detection bell 55 so as to to allow depression of the detection chamber and, on the other hand, to the analysis equipment 56 of so as to conduct the gas contained in the detection chamber 61 to the analysis equipment 56.

La pompe à vide 57 est reliée à la cloche de détection 55 via un tuyau 58 qui est de préférence flexible. Le tuyau 58 est raccordé à un canal qui est ménagé dans le corps principal 100 et débouche dans la chambre de détection 61.The vacuum pump 57 is connected to the detection bell 55 via a pipe 58 which is preferably flexible. The pipe 58 is connected to a channel which is formed in the main body 100 and opens into the detection chamber 61.

Comme représenté sur les figures 2 et 3, le corps principal 100 comporte un noyau rigide 59 et le joint d'étanchéité 60 comporte une enveloppe 63 épousant la forme du noyau rigide 59 et une lèvre d'étanchéité périphérique 64 qui prolonge l'enveloppe 63 vers le bas. L'enveloppe présente un fond 63 qui recouvre la surface supérieure du noyau rigide 59 et une paroi périphérique 74 qui épouse la périphérie du noyau rigide 59. Le fond 63 présente au moins un trou, non représenté, auquel est raccordé de manière étanche le tuyau 58 relié à la pompe à vide 57. Le noyau rigide 59 comporte sur sa surface inférieure 80 un évidement 79 sur toute la longueur du noyau rigide 59. L'évidement 79 permet lors d'une mise en dépression de la chambre de détection 61 d'assurer, malgré un abaissement du noyau rigide 59 vers la membrane 5, 8 dû à une déformation de la lèvre d'étanchéité 64, que la zone de test 62 se trouve toujours en contact fluidique avec la chambre de détection 61. De plus, le noyau rigide 59 comporte également un canal 82, non représenté sur la figure 2 car présent seulement dans un plan passant au niveau du tuyau 58, permettant de relier l'évidement 79 à une surface supérieure 81 du noyau rigide 59. Le canal 82 permet de mettre en communication la chambre de détection 61 avec la pompe à vide 57 et l'équipement d'analyse 56 via le tuyau 58.As shown on the figure 2 and 3 , the main body 100 comprises a rigid core 59 and the seal 60 comprises a casing 63 matching the shape of the rigid core 59 and a peripheral sealing lip 64 which extends the casing 63 downwards. The casing has a bottom 63 which covers the upper surface of the rigid core 59 and a peripheral wall 74 which matches the periphery of the rigid core 59. The bottom 63 has at least one hole, not shown, to which the pipe is connected in leaktight manner. 58 connected to the vacuum pump 57. The rigid core 59 has on its lower surface 80 a recess 79 over the entire length of the rigid core 59. The recess 79 allows during a depression of the detection chamber 61 to ensure, despite a lowering of the rigid core 59 towards the membrane 5, 8 due to a deformation of the sealing lip 64, that the test zone 62 is always in fluid contact with the detection chamber 61. In addition, the rigid core 59 also includes a channel 82, not shown on the picture 2 because present only in a plane passing at the level of the pipe 58, making it possible to connect the recess 79 to an upper surface 81 of the rigid core 59. The channel 82 makes it possible to put the detection chamber 61 in communication with the vacuum pump 57 and analysis equipment 56 via pipe 58.

La lèvre d'étanchéité périphérique 64 est recourbée vers l'extérieur de la cloche de détection 55 et est ainsi configurée pour se fléchir et se plaquer contre la membrane 5, 8 lorsque la chambre étanche 61 est mise en dépression. En d'autres termes, la lèvre d'étanchéité périphérique 64 présente une section présentant une forme générale de L.The peripheral sealing lip 64 is curved towards the outside of the detection bell 55 and is thus configured to bend and press against the membrane 5, 8 when the sealed chamber 61 is placed under depression. In other words, the peripheral sealing lip 64 has a section with the general shape of L.

La portion recourbée vers l'extérieur de la lèvre d'étanchéité périphérique 64 présente une largeur de l'ordre de 15 à 40 mm. La lèvre d'étanchéité périphérique 64 est conformée pour s'adapter à la géométrie de la membrane 5, 8 le long du cordon de soudure à tester. Aussi, sur la figure 3, la lèvre d'étanchéité périphérique 64 comporte des échancrures 65 présentant une forme correspondant à celle des ondulations de la membrane 5, 8 que la cloche de détection 55 est destinée à enjamber lorsqu'elle est en position contre la portion du cordon de soudure 62 à tester.The outwardly curved portion of the peripheral sealing lip 64 has a width of the order of 15 to 40 mm. The peripheral sealing lip 64 is shaped to adapt to the geometry of the membrane 5, 8 along the weld bead to be tested. Also, on the picture 3 , the peripheral sealing lip 64 has notches 65 having a shape corresponding to that of the undulations of the membrane 5, 8 that the detection bell 55 is intended to span when it is in position against the portion of the weld bead 62 to test.

Le joint d'étanchéité 60 est avantageusement réalisé dans un matériau élastomère présentant une dureté comprise entre 20 et 50 Shore A. Le joint d'étanchéité est par exemple réalisé en polyuréthane élastomère, en caoutchouc EPDM, en silicone, en nitrile ou en Viton ®.The seal 60 is advantageously made of an elastomeric material having a hardness of between 20 and 50 Shore A. The seal is by example made of elastomeric polyurethane, EPDM rubber, silicone, nitrile or Viton ® .

La figure 3 illustre également l'axe longitudinal médian 20 de la chambre de détection 61 entourée par la lèvre d'étanchéité périphérique 64. En service, il est souhaitable de bien centrer la chambre de détection 61 sur le cordon de soudure à vérifier, en particulier du fait que la chambre de détection 61 peut être relativement étroite. Pour cela, la cloche de détection 55 peut comporter un dispositif de visée qui est réalisé, sur la figure 3, sous la forme de deux pointes indicatrices 21 qui sont placées aux deux extrémités longitudinales de la cloche de détection et orientées dans l'alignement de l'axe longitudinal médian 20. En variante, une seule des deux pointes indicatrices 21 pourrait être prévue. Les pointes indicatrices 21 sont ici réalisées d'un seul tenant avec la lèvre d'étanchéité périphérique 64, ce qui assure que les pointes indicatrices 21 sont à proximité immédiate de la membrane 5, 8 et limite donc les risques d'erreur de visée par parallaxe. Les pointes indicatrices 21 peuvent cependant être réalisées d'autres manières, par exemple sous la forme de pièces rapportées. Les pointes indicatrices 21 peuvent être fixées à d'autres parties de la cloche de détection 55.The picture 3 also illustrates the median longitudinal axis 20 of the detection chamber 61 surrounded by the peripheral sealing lip 64. In service, it is desirable to properly center the detection chamber 61 on the weld bead to be checked, in particular because that the detection chamber 61 can be relatively narrow. For this, the detection bell 55 may comprise a sighting device which is produced, on the picture 3 , in the form of two indicator spikes 21 which are placed at the two longitudinal ends of the detection bell and oriented in alignment with the median longitudinal axis 20. Alternatively, only one of the two indicator spikes 21 could be provided. The indicator spikes 21 are here made in one piece with the peripheral sealing lip 64, which ensures that the indicator spikes 21 are in the immediate vicinity of the membrane 5, 8 and therefore limits the risk of sighting error by parallax. The indicator spikes 21 can however be produced in other ways, for example in the form of inserts. The indicator spikes 21 can be attached to other parts of the detection bell 55.

La figure 21 illustre un dispositif de visée optique constituée de deux diodes laser 22 attachées aux deux extrémités longitudinales de la cloche de détection 55 et émettant des faisceaux lumineux 23 également orientés dans l'alignement de l'axe longitudinal médian 20. En variante, une seule des deux diodes laser 22 pourrait être prévue. La diode laser 22 peut être placée sur la lèvre d'étanchéité périphérique 64 ou au-dessus de la lèvre d'étanchéité périphérique 64, par exemple sur un élément support 73 qui sera décrit plus bas. De préférence dans ce cas, le faisceau lumineux 23 est incliné légèrement vers le bas pour frapper la membrane 5, 8 et ainsi limiter les risques d'erreur de visée par parallaxe.The figure 21 illustrates an optical sighting device consisting of two laser diodes 22 attached to the two longitudinal ends of the detection bell 55 and emitting light beams 23 also oriented in alignment with the median longitudinal axis 20. Alternatively, only one of the two 22 laser diodes could be provided. The laser diode 22 can be placed on the peripheral sealing lip 64 or above the peripheral sealing lip 64, for example on a support element 73 which will be described below. Preferably in this case, the light beam 23 is inclined slightly downwards to strike the membrane 5, 8 and thus limit the risk of sighting error by parallax.

Dans un mode de réalisation illustré schématiquement sur la figure 4, la cloche de détection 55 est en outre équipée d'un moyen mécanique de pression 66, qui est dans ce mode de réalisation un système de serrage 66, apte à plaquer la lèvre d'étanchéité périphérique 64 contre la membrane 8 à tester de manière à garantir l'étanchéité de la chambre de détection 61. Le système de serrage 66 comporte ici une pince 67 au niveau de chacune des échancrures 65 de la lèvre d'étanchéité périphérique 64. Chaque pince 67 comporte deux branches respectivement disposées de part et d'autre de l'échancrure 65 et configurées pour venir appliquer un effort de serrage de la lèvre d'étanchéité périphérique 64 contre la membrane 8. De manière avantageuse, les branches sont configurées pour serrer la lèvre d'étanchéité périphérique 64 contre la membrane d'étanchéité, à proximité de la base de l'ondulation.In an embodiment schematically illustrated in the figure 4 , the detection bell 55 is also equipped with a mechanical pressure means 66, which in this embodiment is a clamping system 66, capable of pressing the peripheral sealing lip 64 against the membrane 8 to be tested in such a way to guarantee the sealing of the detection chamber 61. The clamping system 66 here comprises a clamp 67 at the level of each of the notches 65 of the peripheral sealing lip 64. Each clamp 67 comprises two branches respectively arranged on either side other of the notch 65 and configured to apply a clamping force of the peripheral sealing lip 64 against the membrane 8. Advantageously, the branches are configured to clamp the peripheral sealing lip 64 against the membrane of sealing, near the base of the corrugation.

Par ailleurs, dans le mode de réalisation représenté, le système de serrage 66 comporte en outre, au niveau de chacune des extrémités longitudinales de la cloche de détection 55, un doigt 68, mobile, qui est configuré pour venir plaquer l'une des extrémités longitudinales de la lèvre d'étanchéité périphérique 64 contre la membrane 8.Furthermore, in the embodiment shown, the clamping system 66 further comprises, at each of the longitudinal ends of the detection bell 55, a finger 68, movable, which is configured to press against one of the ends longitudinal of the peripheral sealing lip 64 against the membrane 8.

La figure 5 illustre un joint d'étanchéité 60 selon un mode de réalisation alternatif. Ce joint d'étanchéité 60 est conformé pour s'adapter à une membrane 5 dans laquelle les ondulations font saillie vers l'extérieur de la cuve. Une telle membrane est par exemple une membrane secondaire 5 selon la technologie Mark V. Aussi, la lèvre d'étanchéité périphérique 64 comporte des zones en saillie 69 destinées à venir s'insérer à l'intérieur des ondulations de la membrane 5.The figure 5 illustrates a gasket 60 according to an alternative embodiment. This seal 60 is shaped to adapt to a membrane 5 in which the corrugations protrude towards the outside of the tank. Such a membrane is, for example, a secondary membrane 5 according to Mark V technology. Also, the peripheral sealing lip 64 includes projecting zones 69 intended to be inserted inside the undulations of the membrane 5.

Une procédure pour détecter un défaut d'étanchéité d'un cordon de soudure est la suivante.A procedure for detecting a seal defect in a weld bead is as follows.

Dans un premier temps l'on dispose la cloche de détection 55 en regard de la portion du cordon de soudure 62 à tester, qui longe un bord rectiligne d'une tôle rectangulaire, tel que représenté sur la figure 6.Initially, the detection bell 55 is placed facing the portion of the weld bead 62 to be tested, which runs along a straight edge of a rectangular sheet, as shown in the figure 6 .

Il convient de s'assurer que la cloche de détection 55 est convenablement centrée par rapport au cordon de soudure 62 de sorte que les deux parties latérales de la portion recourbée de la lèvre d'étanchéité périphérique 64 soient disposées de part et d'autre du cordon de soudure 62.It should be ensured that the detection bell 55 is suitably centered with respect to the weld bead 62 so that the two lateral parts of the curved portion of the peripheral sealing lip 64 are arranged on either side of the weld bead 62.

Pour cela, la figure 6 illustre également le dispositif de visée, réalisé ici sous la forme des deux pointes indicatrices 21, qui sont placées précisément en superposition du cordon de soudure 62 par l'opérateur pour ainsi aligner l'axe longitudinal médian 20 de la chambre de détection avec le cordon de soudure 62. Dans le cas du dispositif de visée optique de la figure 21, ce sont les faisceaux lumineux 23 qui seront placées précisément en superposition du cordon de soudure 62.For this, the figure 6 also illustrates the sighting device, made here in the form of the two indicator tips 21, which are placed precisely in superposition of the weld bead 62 by the operator to thus align the median longitudinal axis 20 of the detection chamber with the bead weld 62. In the case of the optical sighting device of the figure 21 , it is the light beams 23 which will be placed precisely superimposed on the weld bead 62.

La figure 6 illustre aussi schématiquement le contour 30 de la chambre de détection 61, à savoir la ligne de contact étanche entre la lèvre d'étanchéité périphérique 64 et la membrane 5, 8.The figure 6 also schematically illustrates the contour 30 of the detection chamber 61, namely the sealed contact line between the peripheral sealing lip 64 and the membrane 5, 8.

La pompe à vide 57 est alors mise en fonctionnement afin de mettre la chambre de détection 61 en dépression et favoriser la migration du gaz au travers des zones défectueuses du cordon de soudure 62.The vacuum pump 57 is then put into operation in order to put the detection chamber 61 under vacuum and promote the migration of gas through the defective zones of the weld bead 62.

Dès que la pression à l'intérieur de la chambre de détection 61 passe en dessous d'un seuil de pression Ps, un flux de gaz est conduit de la chambre de détection 61 vers l'équipement d'analyse 56 et un taux de fuite ϕ du gaz prédéfini, par exemple gaz traceur, est mesuré pendant une durée minimale Tm. Le taux de fuite ϕ est alors comparé à un seuil ϕs.As soon as the pressure inside the detection chamber 61 drops below a pressure threshold Ps, a flow of gas is conducted from the detection chamber 61 to the analysis equipment 56 and a leak rate ϕ of the predefined gas, for example tracer gas, is measured for a minimum duration Tm. The leak rate ϕ is then compared to a threshold ϕs.

Si le taux de fuite ϕ est inférieur au seuil ϕs, alors il est conclu que la portion testée du cordon de soudure 62 ne présente pas de défaut d'étanchéité. Dans ce cas, la cloche de détection 55 est alors détachée de la membrane 5, 8 par libération de la dépression dans la chambre de détection 61, par exemple par ouverture d'une entrée de gaz 71 représentée sur la figure 7. Puis la cloche de détection 55 est disposée en regard d'une portion adjacente du cordon de soudure 62 en assurant un recouvrement entre les deux portions successivement testées de manière à garantir que l'étanchéité du cordon de soudure 62 ait été testée sur toute la longueur dudit cordon de soudure 62.If the leak rate ϕ is less than the threshold ϕs, then it is concluded that the tested portion of the weld bead 62 does not exhibit any sealing defect. In this case, the detection bell 55 is then detached from the membrane 5, 8 by releasing the depression in the detection chamber 61, for example by opening a gas inlet 71 shown on the figure 7 . Then the detection bell 55 is arranged facing an adjacent portion of the weld bead 62 ensuring an overlap between the two portions successively tested so as to guarantee that the tightness of the weld bead 62 has been tested over the entire length. of said weld bead 62.

Au contraire, si le taux de fuite ϕ est supérieur ou égal au seuil ϕs, alors il est conclu que la portion testée du cordon de soudure 62 présente un défaut d'étanchéité. Des mesures de soudure correctives sont alors mise en œuvre afin de corriger le défaut.On the contrary, if the leak rate ϕ is greater than or equal to the threshold ϕs, then it is concluded that the tested portion of the weld bead 62 has a sealing defect. Corrective welding measures are then implemented to correct the defect.

A titre d'exemple, pour une concentration en hélium dans l'espace thermiquement isolant de l'ordre de 20 %, le seuil de pression en dessous duquel le taux de fuite est mesuré est compris entre 10 et 1000 Pa absolu, de préférence inférieure à 100 Pa absolu. A titre d'exemple, la durée minimale de mesure du taux de fuite est de 5 secondes et le seuil ϕs est de l'ordre de 1,0.10-6 Pa.m3.s-1.By way of example, for a helium concentration in the thermally insulating space of the order of 20%, the pressure threshold below which the leak rate is measured is between 10 and 1000 Pa absolute, preferably lower at 100 Pa absolute. By way of example, the minimum duration for measuring the leak rate is 5 seconds and the threshold ϕs is of the order of 1.0.10 -6 Pa.m 3 .s -1 .

La figure 7 représente un dispositif de détection de fuite 54 selon un autre mode de réalisation. Ce mode de réalisation diffère du mode de réalisation décrit précédemment en ce qu'il comporte en outre une chambre d'homogénéisation 70 qui est disposée entre la chambre de détection 61 et l'équipement d'analyse 56 et en ce que la cloche de détection 55 comporte une entrée de gaz 71.The figure 7 shows a leak detection device 54 according to another embodiment. This embodiment differs from the embodiment described above in that it further comprises a homogenization chamber 70 which is arranged between the detection chamber 61 and the analysis equipment 56 and in that the detection bell 55 has a gas inlet 71.

L'entrée de gaz 71 est équipée d'un robinet permettant d'établir ou d'interrompre un écoulement d'air ambiant vers la chambre de détection 61. La chambre d'homogénéisation 70 est raccordée à une extrémité de la chambre de détection 61 tandis que l'entrée de gaz 71 est raccordée à l'extrémité opposée de la chambre de détection 61.The gas inlet 71 is equipped with a tap making it possible to establish or interrupt a flow of ambient air towards the detection chamber 61. The homogenization chamber 70 is connected to one end of the detection chamber 61 while the gas inlet 71 is connected to the opposite end of the detection chamber 61.

Le mode de fonctionnement du dispositif de détection de fuite 54 est le suivant.The mode of operation of the leak detection device 54 is as follows.

Lorsque la cloche de détection 55 est disposée en regard de la portion du cordon de soudure 62 à tester, le robinet de l'entrée de gaz 71 est fermé et la pompe à vide 57 est mise en fonctionnement afin de mettre la chambre de détection 61 en dépression. Dès que la pression à l'intérieur de la chambre de détection 61 passe en dessous d'un seuil de pression Ps, le robinet de l'entrée de gaz 71 est ouvert et l'ensemble du gaz préalablement contenu dans la chambre étanche est transféré vers la chambre d'homogénéisation 70. La chambre d'homogénéisation 70 présente un volume supérieur à celui de de la chambre de détection 61 et comporte par exemple un système de piston permettant d'aspirer précisément l'intégralité du gaz contenu dans la chambre de détection 61.When the detection bell 55 is positioned opposite the portion of the weld bead 62 to be tested, the gas inlet valve 71 is closed and the vacuum pump 57 is put into operation in order to put the detection chamber 61 in depression. As soon as the pressure inside the detection chamber 61 drops below a pressure threshold Ps, the gas inlet valve 71 is opened and all of the gas previously contained in the sealed chamber is transferred towards the homogenization chamber 70. The homogenization chamber 70 has a volume greater than that of the chamber of detection 61 and comprises for example a piston system making it possible to precisely suck up all the gas contained in the detection chamber 61.

Le gaz contenu dans la chambre d'homogénéisation 70 est ensuite transféré en direction de l'équipement d'analyse 56 afin de déterminer un taux de fuite ϕ en gaz.The gas contained in the homogenization chamber 70 is then transferred in the direction of the analysis equipment 56 in order to determine a gas leak rate ϕ.

Un tel mode de réalisation est avantageux en ce qu'il permet de diminuer le temps de diffusion du gaz à l'intérieur de la cloche de détection 55 et permet ainsi de diminuer la durée minimale de mesure. Ceci est notamment avantageux lorsque le temps pour que le gaz migre d'une extrémité à une autre de la cloche de détection 55 est susceptible d'être long en raison d'une longueur importante de la cloche de détection 55 et/ou lorsque la dépression régnant à l'intérieur de la chambre de détection 61 est insuffisante.Such an embodiment is advantageous in that it makes it possible to reduce the diffusion time of the gas inside the detection bell 55 and thus makes it possible to reduce the minimum duration of measurement. This is particularly advantageous when the time for the gas to migrate from one end to another of the detection bell 55 is likely to be long due to a significant length of the detection bell 55 and/or when the depression prevailing inside the detection chamber 61 is insufficient.

La figure 8 représente une cloche de détection 55 selon un troisième mode de réalisation. La cloche de détection 55 de la figure 8 est conçue similairement à la cloche de détection 55 de la figure 4 mais diffère notamment concernant le moyen mécanique de pression 66. En effet, la cloche de détection 55 comprend un corps principal 100 s'étendant dans une direction longitudinale, un joint d'étanchéité 60 souple fixé sur le corps principal 100 et un moyen mécanique de pression 66 porté par le corps principal et configuré pour exercer une pression dirigée vers la membrane 5, 8 sur le joint d'étanchéité 60. Le corps principal 100 comporte un noyau rigide 59. Le noyau rigide 59 comporte un canal 82 permettant de relier une surface inférieure 80 à une surface supérieure 81 du noyau rigide 59. Le canal 82 permet de mettre en communication la chambre de détection 61 à la sortie de gaz 78.The figure 8 represents a detection bell 55 according to a third embodiment. The detection bell 55 of the figure 8 is designed similarly to the detection bell 55 of the figure 4 but differs in particular concerning the mechanical pressure means 66. Indeed, the detection bell 55 comprises a main body 100 extending in a longitudinal direction, a flexible seal 60 fixed to the main body 100 and a mechanical means of pressure 66 carried by the main body and configured to exert a pressure directed towards the membrane 5, 8 on the seal 60. The main body 100 comprises a rigid core 59. The rigid core 59 comprises a channel 82 making it possible to connect a lower surface 80 to an upper surface 81 of the rigid core 59. The channel 82 allows communication between the detection chamber 61 and the gas outlet 78.

Le joint d'étanchéité 60 comporte une enveloppe 63 fixée au noyau rigide 59 par des moyens de fixation 110, par exemple consistant en un cerclage entourant toute la circonférence du noyau rigide 59 et du joint d'étanchéité 60 et fixant ces deux éléments 59/60 l'un à l'autre par l'intermédiaire d'un élément mécanique de fixation tels que des vis. Le joint d'étanchéité 60 comporte également une lèvre d'étanchéité périphérique 64 liée à l'enveloppe 63 et présentant un contour fermé permettant d'entourer la partie du cordon de soudure 62 à tester. La lèvre périphérique 64 est de plus recourbée en direction opposée au corps principal 100 de manière à avoir une partie de la lèvre périphérique 64 sensiblement parallèle à la membrane 5, 8. La lèvre d'étanchéité périphérique 64 présente également une pluralité d'échancrures 65 espacées sur sa circonférence, les échancrures 65 ayant la forme des ondulations de la membrane 5, 8 à tester. Ainsi, lors du placement de la cloche de détection 55 sur la membrane 5, 8, les échancrures 55 permettent à la cloche de détection 55 de s'adapter à la forme ondulée de la membrane 5, 8. Le corps principal 100 et l'élément porteur 73 sont notamment traversés par une sortie de gaz 78 permettant lors de la mise en dépression de la chambre de détection 61 d'évacuer le gaz.The seal 60 comprises an envelope 63 fixed to the rigid core 59 by fastening means 110, for example consisting of a strapping surrounding the entire circumference of the rigid core 59 and of the seal 60 and fixing these two elements 59/ 60 to each other by means of a mechanical fixing element such as screws. The seal 60 also includes a peripheral sealing lip 64 connected to the casing 63 and having a closed contour making it possible to surround the part of the weld bead 62 to be tested. The peripheral lip 64 is moreover curved in the opposite direction to the main body 100 so as to have a part of the peripheral lip 64 substantially parallel to the membrane 5, 8. The peripheral sealing lip 64 also has a plurality of indentations 65 spaced apart on its circumference, the notches 65 having the shape of the undulations of the membrane 5, 8 to be tested. Thus, when placing the detection bell 55 on the membrane 5, 8, the notches 55 allow the detection bell 55 to adapt to the wavy shape of the membrane 5, 8. The body main 100 and the carrier element 73 are in particular traversed by a gas outlet 78 allowing, when the depression of the detection chamber 61 to evacuate the gas.

Un élément support 73 s'étend sur toute la longueur du corps principal 100 au-dessus de celui-ci et est fixé au corps principal 100. Des poignées de manutention 76 sont fixées aux deux extrémités longitudinales de l'élément support 73 de manière à permettre la manipulation de la cloche de détection 55 par un opérateur et éventuellement d'actionner le moyen mécanique de pression par un effort de l'opérateur.A support element 73 extends over the entire length of the main body 100 above it and is fixed to the main body 100. Handling handles 76 are fixed to the two longitudinal ends of the support element 73 so as to allow the manipulation of the detection bell 55 by an operator and possibly to actuate the mechanical means of pressure by an effort of the operator.

Le moyen mécanique de pression 66 est composé d'une pluralité d'éléments de pression 72 qui sont sous la forme de lames courbées 72 réparties sur la lèvre d'étanchéité 64 et qui sont fixées par des moyens de fixation 77 à l'élément support 73. Les lames courbées 72 sont déformables élastiquement de manière à, lorsqu'elles sont déformées, exercer un effort de retour élastique sur la lèvre d'étanchéité 64 afin de la plaquer sur la membrane 5, 8. Pour fiabiliser l'étanchéité de la chambre de détection 61, il semble judicieux de plaquer la lèvre d'étanchéité 64 dans les zones où le risque de décollement est plus important. C'est pourquoi des lames courbées 72 sont situées notamment aux bases des échancrures 64 de la lèvre d'étanchéité 64 et aux extrémités longitudinales de la cloche de détection 55 sur la lèvre d'étanchéité 64.The mechanical pressure means 66 is composed of a plurality of pressure elements 72 which are in the form of curved blades 72 distributed over the sealing lip 64 and which are fixed by fixing means 77 to the support element. 73. The curved blades 72 are elastically deformable so as to, when they are deformed, exert an elastic return force on the sealing lip 64 in order to press it against the membrane 5, 8. To make the sealing of the detection chamber 61, it seems judicious to flatten the sealing lip 64 in the areas where the risk of detachment is greater. This is why curved blades 72 are located in particular at the bases of the notches 64 of the sealing lip 64 and at the longitudinal ends of the detection bell 55 on the sealing lip 64.

Une pluralité de lames courbées 72 sont fixées à l'une de leur extrémité à l'élément support 73 tandis que l'autre extrémité est placée sur la lèvre d'étanchéité 64. Ces lames 72 sont notamment placées sur les extrémités de la cloche de détection 55. D'autres lames courbées 72 sont quant à elle fixées en leur milieu à l'élément support 73 alors que leurs deux extrémités sont placées sur la lèvre d'étanchéité 64 de manière à appliquer une pression sur deux zones différentes, ces lames 72 étant notamment placées entre deux échancrures 65.A plurality of curved blades 72 are fixed at one of their ends to the support element 73 while the other end is placed on the sealing lip 64. These blades 72 are in particular placed on the ends of the detection 55. Other curved blades 72 are fixed in their middle to the support element 73 while their two ends are placed on the sealing lip 64 so as to apply pressure to two different zones, these blades 72 being notably placed between two notches 65.

Les lames courbées 72 présentent à chacune de leur extrémité en contact avec la lèvre d'étanchéité 64 un manchon cylindrique 75. Le manchon cylindrique 75 permet notamment un appui homogène sur la lèvre d'étanchéité 64 en évitant tout poinçonnant qui pourrait dégrader l'intégrité de la lèvre d'étanchéité 64. Le manchon cylindrique 75 s'étend dans une direction orthogonale à la direction longitudinale du corps principal 100. La longueur d'un manchon cylindrique 75 est de plus sensiblement égale à la dimension de la partie de la lèvre d'étanchéité 64 faisant saillie du corps principal 100, dans la direction où s'étend le manchon cylindrique 75. Ainsi le manchon cylindrique 75 permet au moyen mécanique de pression 66 d'exercer une pression de manière efficace sur la lèvre d'étanchéité.The curved blades 72 have at each of their ends in contact with the sealing lip 64 a cylindrical sleeve 75. The cylindrical sleeve 75 allows in particular a homogeneous support on the sealing lip 64 avoiding any punching which could degrade the integrity of the sealing lip 64. The cylindrical sleeve 75 extends in a direction orthogonal to the longitudinal direction of the main body 100. The length of a cylindrical sleeve 75 is moreover substantially equal to the dimension of the part of the lip seal 64 projecting from the main body 100, in the direction in which the cylindrical sleeve 75 extends. Thus the cylindrical sleeve 75 allows the mechanical pressure means 66 to exert pressure effectively on the sealing lip.

Lors du placement de la cloche de détection de fuite 55 sur la zone à tester, il faut s'assurer que le moyen mécanique de pression 66 plaque bien de manière étanche le joint d'étanchéité 60 pour pouvoir tester l'étanchéité de la soudure convenablement. Une problématique est donc de s'assurer que le moyen mécanique de pression 66 joue bien son rôle tout autour de la lèvre d'étanchéité périphérique 64. Or, la zone à tester et notamment aux extrémités de la cloche de détection 55 peut être une zone de jonction entre plusieurs tôles métalliques ondulées, par exemple quatre tôles métalliques ondulées, de sorte que la zone n'est pas entièrement plane mais comporte des nivelages rendant difficile de plaquer le joint d'étanchéité 60.When placing the leak detection bell 55 on the area to be tested, it must be ensured that the mechanical pressure means 66 seals the seal well. seal 60 to be able to test the tightness of the weld properly. A problem is therefore to ensure that the mechanical pressure means 66 plays its role well all around the peripheral sealing lip 64. However, the zone to be tested and in particular at the ends of the detection bell 55 can be a zone junction between several corrugated metal sheets, for example four corrugated metal sheets, so that the area is not entirely flat but has levels making it difficult to flatten the seal 60.

La figure 13 représente une cloche de détection 55 selon un quatrième mode de réalisation où le moyen mécanique de pression 66 a été renforcé aux extrémités de la cloche de détection 55 pour palier à la non planéité de la zone. La cloche de détection 55 de la figure 13 est conçue similairement à la cloche de détection 55 de la figure 8 mais diffère notamment par la forme de la chambre de détection qui présente deux zones circulaires aux deux extrémités longitudinales qui sont plus larges qu'une bande rectiligne centrale. D'autres différences concernent le moyen mécanique de pression 66. En effet, la cloche de détection 55 de la figure 13 comprend également un corps principal 100 s'étendant dans une direction longitudinale, un joint d'étanchéité 60 souple fixé sur le corps principal 100 et un moyen mécanique de pression 66 porté par le corps principal et configuré pour exercer une pression dirigée vers la membrane 5, 8 sur le joint d'étanchéité 60. Toutefois, le moyen mécanique de pression 66 comprend ici des éléments de pression 72 et des éléments de pression d'extrémité 87.The figure 13 shows a detection bell 55 according to a fourth embodiment where the mechanical pressure means 66 has been reinforced at the ends of the detection bell 55 to compensate for the unevenness of the zone. The detection bell 55 of the figure 13 is designed similarly to the detection bell 55 of the figure 8 but differs in particular by the shape of the detection chamber which has two circular zones at the two longitudinal ends which are wider than a central rectilinear band. Other differences relate to the mechanical means of pressure 66. Indeed, the detection bell 55 of the figure 13 also comprises a main body 100 extending in a longitudinal direction, a flexible seal 60 fixed to the main body 100 and a mechanical pressure means 66 carried by the main body and configured to exert a pressure directed towards the membrane 5 , 8 on the seal 60. However, the mechanical pressure means 66 here comprises pressure elements 72 and end pressure elements 87.

Les éléments de pression 72 comportent chacun une lame courbée 72 dont au moins une extrémité vient en butée sur la base d'une échancrure 62. Les lames courbées 72 situées entre deux échancrures contiguës comportent quant à elle l'une de leurs extrémités qui est située contre la base de l'une des échancrures 65 et l'autre des extrémités qui est située contre la base de l'autre des échancrures 65. Les éléments de pression 72 sont ici, comme illustré sur la figure 14, fixés par des moyens de fixation 77 comportant chacun un pion 83. Les pions 83 comportent chacun une tige 85 montée mobile sur un corps 84. La tige 85 comporte une extrémité en appui contre l'une des lames courbées 72. Le corps 84 est fixé à l'élément de support 73. Le pion 83 comporte également un ressort 86 reliant la tige 85 au corps 84, le ressort 86 agissant entre le corps 84 et la tige 85 afin de positionner l'extrémité de la tige 85 en appui contre la lame courbée 72. Ainsi, le ressort 86 est configuré pour exercer une force de rappel sur la lame courbée 72 de sorte que la lame courbée 72 vienne plaquer la lèvre d'étanchéité 64 contre le pied de l'ondulation.The pressure elements 72 each comprise a curved blade 72, at least one end of which comes into abutment on the base of a notch 62. The curved blades 72 located between two contiguous notches comprise one of their ends which is located against the base of one of the notches 65 and the other of the ends which is located against the base of the other of the notches 65. The pressure elements 72 are here, as illustrated in the figure 14 , fixed by fastening means 77 each comprising a pin 83. The pins 83 each comprise a rod 85 movably mounted on a body 84. The rod 85 has one end resting against one of the curved blades 72. The body 84 is fixed to the support element 73. The pin 83 also comprises a spring 86 connecting the rod 85 to the body 84, the spring 86 acting between the body 84 and the rod 85 in order to position the end of the rod 85 in abutment against the curved blade 72. Thus, the spring 86 is configured to exert a return force on the curved blade 72 so that the curved blade 72 presses the sealing lip 64 against the root of the corrugation.

Les éléments de pression d'extrémité 87 sont situés aux deux extrémités de la lèvre d'étanchéité 64 dans une direction longitudinale, soit aux deux extrémités de la cloche de détection de fuite 55 étant donné que cette dernière présente une forme générale longitudinale. Les éléments de pression d'extrémité 87 peuvent être conçus selon une pluralité de variantes distinctes combinables ou non sur une même cloche de détection de fuite 55. Par soucis de concision, trois variantes des éléments de pression d'extrémité 87 sont illustrées sur la figure 13 sur une même cloche de détection de fuite 55.The end pressure elements 87 are located at both ends of the sealing lip 64 in a longitudinal direction, that is to say at the two ends of the leak detection bell 55 since the latter has a general shape longitudinal. The end pressure elements 87 can be designed according to a plurality of distinct variants which may or may not be combined on the same leak detection bell 55. For the sake of conciseness, three variants of the end pressure elements 87 are illustrated on the figure 13 on the same leak detection bell 55.

Les figures 15 à 17 représentent les trois variantes des éléments de pression d'extrémité 87. Comme illustré sur la figure 15 selon la première variante, l'élément de pression d'extrémité 87 comprend un pion d'extrémité 88. Les pions d'extrémité 88 comportent chacun une tige 90 montée mobile sur un corps 89. Un élément d'appui allongé 91 est fixé à une extrémité de la tige 90, l'élément d'appui allongé 91 venant en appui contre la lèvre d'étanchéité 64. Le corps 89 est fixé à l'élément de support 73. Le pion d'extrémité 88 comporte également un ressort 86 reliant la tige 90 au corps 89, le ressort 86 agissant entre le corps 89 et la tige 90 afin de positionner l'élément d'appui allongé 91 contre la lèvre d'étanchéité 64. Ainsi, le ressort 86 est configuré pour exercer une force de rappel sur l'élément d'appui allongé 91 de sorte que l'élément d'appui allongé 91 vienne plaquer la lèvre d'étanchéité 64 contre la zone à tester. De cette manière, l'effort de rappel est exercé sur la lèvre d'étanchéité 64 sur toute la longueur de l'élément d'appui allongé 91. Dans le cas de la première variante de la figure 15, chaque élément d'appui allongé 91 n'est fixé qu'à une seule tige 90 d'un pion d'extrémité 88.The figures 15 to 17 represent the three variants of the end pressure elements 87. As illustrated in the figure 15 according to the first variant, the end pressure element 87 comprises an end pin 88. The end pins 88 each comprise a rod 90 movably mounted on a body 89. An elongated support element 91 is fixed to one end of the rod 90, the elongated support element 91 bearing against the sealing lip 64. The body 89 is fixed to the support element 73. The end pin 88 also comprises a spring 86 connecting rod 90 to body 89, spring 86 acting between body 89 and rod 90 to position elongated bearing member 91 against sealing lip 64. Thus, spring 86 is configured to exert a force reminder on the elongated support element 91 so that the elongated support element 91 presses the sealing lip 64 against the area to be tested. In this way, the return force is exerted on the sealing lip 64 over the entire length of the elongated support element 91. In the case of the first variant of the figure 15 , each elongated support element 91 is attached to only one rod 90 of an end pin 88.

Une deuxième variante des éléments de pression d'extrémité 87 est illustrée sur la figure 16. La deuxième variante diffère de la première variante par l'élément d'appui allongé 91 des pions d'extrémité 88, les autres caractéristiques des éléments de pression d'extrémité 87 sont conservées. Dans cette variante, l'élément d'appui allongé 91 est fixé à une extrémité d'une tige 90 d'un premier pion d'extrémité 88 et à une extrémité d'une tige 90 d'un deuxième pion d'extrémité 88 adjacent au premier pion d'extrémité 88. L'élément d'appui allongé 91 est donc ici plus long que dans la première variante et est ainsi plaqué par deux pions d'extrémité 88 répartis sur sa longueur de sorte à former un appui d'une longueur plus importante sur la lèvre d'étanchéité 64.A second variant of the end pressure elements 87 is illustrated in the figure 16 . The second variant differs from the first variant by the elongated support element 91 of the end pins 88, the other characteristics of the end pressure elements 87 are retained. In this variant, the elongated support element 91 is fixed to one end of a rod 90 of a first end pin 88 and to one end of a rod 90 of a second adjacent end pin 88 to the first end pin 88. The elongated support element 91 is therefore here longer than in the first variant and is thus pressed by two end pins 88 distributed over its length so as to form a support of one greater length on the sealing lip 64.

Une troisième variation des éléments de pression d'extrémité 87 est illustrée sur la figure 17. Dans cette variante, l'élément de pression d'extrémité 87 comprend une pluralité d'éléments de réglage 92 formant une ligne d'éléments. L'élément de réglage 92 comprend une tige 93 s'étendant en direction de la lèvre d'étanchéité 64 et perpendiculairement à la zone à tester et une extrémité 94 dont la position est réglable dans une direction longitudinale de la tige de sorte à venir en contact avec la lèvre d'étanchéité 64 après réglage de la tige 93. Ainsi, il est possible de régler plus finement l'élément de pression d'extrémité 87 grâce aux éléments de réglage 92 afin d'épouser plus précisément la zone à tester et donc d'améliorer l'étanchéité de la chambre de détection 61.A third variation of the end pressure elements 87 is illustrated in the figure 17 . In this variant, the end pressure element 87 comprises a plurality of adjustment elements 92 forming a line of elements. The adjustment element 92 comprises a rod 93 extending in the direction of the sealing lip 64 and perpendicular to the zone to be tested and an end 94 whose position is adjustable in a longitudinal direction of the rod so as to come into contact with the sealing lip 64 after adjustment of the rod 93. Thus, it is possible to adjust the end pressure element 87 more finely thanks to the adjustment elements 92 in order to marry more precisely the zone to be tested and therefore to improve the tightness of the detection chamber 61.

La figure 17 illustre aussi une semelle de répartition 95 qui peut être agencée entre les extrémités 94 des tiges 93 et la surface supérieure de la lèvre d'étanchéité 64, afin de limiter le risque de poinçonnement de la lèvre d'étanchéité 64 et ainsi accroitre sa durabilité. La semelle de répartition 95 peut être une plaque allongée de forme générale rectiligne ou, comme représentée, arquée pour suivre le contour de la lèvre d'étanchéité 64. Sa matière peut être une résine plastique rigide. De préférence, des manchons de liaison sous formés saillants sur la surface supérieure de la semelle de répartition 95 pour accueillir les extrémités 94 et ainsi fixer la semelle de répartition 95 par rapport aux tiges 93.The figure 17 also illustrates a distribution sole 95 which can be arranged between the ends 94 of the rods 93 and the upper surface of the sealing lip 64, in order to limit the risk of puncturing of the sealing lip 64 and thus increase its durability. The distribution plate 95 can be an elongated plate of generally straight shape or, as shown, arcuate to follow the contour of the sealing lip 64. Its material can be a rigid plastic resin. Preferably, sub-formed connecting sleeves protrude from the upper surface of the distribution sole 95 to accommodate the ends 94 and thus fix the distribution sole 95 with respect to the rods 93.

Il va être décrit par la suite un procédé d'utilisation d'une cloche de détection de fuite 65 telle qu'illustrée à la figure 8 dans un dispositif de détection de fuite 54 comprenant ladite cloche 65, une pompe à vide 57 raccordée à la chambre de détection 61 via la sortie de gaz 78 et un équipement d'analyse 56. L'utilisation d'un tel dispositif de détection 54 permet de contrôler l'étanchéité d'un cordon de soudure 62 entre deux tôles ondules d'une membrane d'étanchéité 5, 8.There will be described below a method of using a leak detection bell 65 as illustrated in figure 8 in a leak detection device 54 comprising said bell 65, a vacuum pump 57 connected to the detection chamber 61 via the gas outlet 78 and analysis equipment 56. The use of such a detection device 54 makes it possible to check the tightness of a weld bead 62 between two corrugated sheets of a sealing membrane 5, 8.

Tout d'abord, la cloche de détection 55 est placée sur la zone à tester l'étanchéité ici une partie du cordon de soudure 62, par exemple par un ou plusieurs opérateurs via les poignées de manutention 76. Pour cela, le corps principal 100 de la cloche de détection 55 est placé au-dessus du cordon de soudure 62 de manière que la longueur du corps principal 100 soit alignée avec et centrée sur le cordon de soudure 62. Le cas échéant, un dispositif de visée décrit plus haut peut être employé pour cela. Ainsi, la lèvre d'étanchéité 64 se trouve de part et d'autre du cordon de soudure 62 et entoure complètement la zone du cordon de soudure 62 à tester pour former avec le corps principal 100 et la membrane 5, 8 une chambre de détection 61 étanche, comme visible sur la figure 9.First of all, the detection bell 55 is placed on the area to be tested for leaktightness, here a part of the weld bead 62, for example by one or more operators via the handling handles 76. For this, the main body 100 of the detection bell 55 is placed above the weld bead 62 so that the length of the main body 100 is aligned with and centered on the weld bead 62. If necessary, an aiming device described above can be employed for this. Thus, the sealing lip 64 is located on either side of the weld bead 62 and completely surrounds the area of the weld bead 62 to be tested to form with the main body 100 and the membrane 5, 8 a detection chamber 61 waterproof, as seen on the figure 9 .

Après que la cloche de détection 55 a été placée sur le cordon de soudure 62, la cloche de détection 55 se fixe comme une ventouse sur la membrane 5, 8 grâce à la force de dépression activée par la pompe à vide 57. Cette force de dépression active, le cas échéant, le moyen mécanique de pression 66 de manière qu'il redirige la pression afin de presser la lèvre d'étanchéité 64 sur la membrane 5, 8 dans certaines zones bien définies.After the detection bell 55 has been placed on the weld bead 62, the detection bell 55 is fixed like a suction cup on the membrane 5, 8 thanks to the depression force activated by the vacuum pump 57. This force of depression activates, if necessary, the mechanical pressure means 66 so that it redirects the pressure in order to press the sealing lip 64 on the membrane 5, 8 in certain well-defined areas.

Lorsque le moyen mécanique de pression 66 subit un effort sur l'élément support 73, l'élément support 73 retransmet l'effort aux lames courbées 72 via leurs fixations respectives ce qui tend à déformer élastiquement les lames courbées 72. De ce fait et par retour élastique, les lames courbées 72 transmettent l'effort à la lèvre d'étanchéité 64 via les manchons cylindriques 75 aux zones où le décollement de la lèvre d'étanchéité est le plus probable à savoir les extrémités longitudinales du corps principal 100 et les bases des échancrures 65.When the mechanical pressure means 66 undergoes a force on the support element 73, the support element 73 retransmits the force to the curved blades 72 via their respective fixings which tends to elastically deform the curved blades 72. As a result and by elastic return, the curved blades 72 transmit the force to the sealing lip 64 via the cylindrical sleeves 75 to the zones where the detachment of the sealing lip is most likely, namely the longitudinal ends of the main body 100 and the bases indentations 65.

La pompe à vide 57 crée une dépression dans la chambre de détection 61 via le canal 82 et la sortie de gaz 78. La souplesse de la lèvre d'étanchéité 64 entraine une déformation de celle-ci lors de la dépression de la chambre de détection 61 tendant à diminuer le volume de la chambre de détection 61. En effet, la lèvre d'étanchéité 64 se rapproche ainsi de part et d'autre du cordon de soudure 62 comme visible sur la figure 10. Dès lors que la pression à l'intérieur de la chambre de détection 61 passe en dessous d'un seuil de pression Ps, les gaz présents dans la chambre de détection 61 sont conduits vers l'équipement d'analyse 56.The vacuum pump 57 creates a depression in the detection chamber 61 via the channel 82 and the gas outlet 78. The flexibility of the sealing lip 64 causes a deformation of the latter when the depression of the detection chamber 61 tending to reduce the volume of the detection chamber 61. Indeed, the sealing lip 64 thus approaches on either side of the weld bead 62 as visible on the figure 10 . As soon as the pressure inside the detection chamber 61 drops below a pressure threshold Ps, the gases present in the detection chamber 61 are led to the analysis equipment 56.

L'équipement d'analyse 56 analyse alors au court d'une durée de mesure Tm la concentration en gaz des gaz présents dans la chambre de détection 61 de manière à obtenir une valeur représentative de l'évolution de la concentration. Cette valeur représentative est alors comparée à une valeur seuil de manière à déterminer si la partie du cordon de soudure 62 testée présente ou non un défaut d'étanchéité.The analysis equipment 56 then analyzes during a measurement time Tm the gas concentration of the gases present in the detection chamber 61 so as to obtain a value representative of the change in concentration. This representative value is then compared with a threshold value so as to determine whether or not the part of the weld bead 62 tested has a sealing defect.

Si la valeur mesurée est inférieure à la valeur seuil, alors il est conclu que la partie testée ne présente pas de défaut d'étanchéité et dans ce cas, la cloche de détection 55 est alors disposée en regard d'une portion adjacente du cordon de soudure 62 en assurant un recouvrement entre les deux portions successivement testées de manière à garantir que l'étanchéité du cordon de soudure 62 ait été testée sur toute la longueur dudit cordon de soudure 62.If the measured value is lower than the threshold value, then it is concluded that the tested part does not present any sealing defect and in this case, the detection bell 55 is then placed opposite an adjacent portion of the bead of weld 62 by ensuring an overlap between the two successively tested portions so as to guarantee that the tightness of the weld bead 62 has been tested over the entire length of said weld bead 62.

Si la valeur mesurée est supérieure ou égale à la valeur seuil, alors il est conclu que la partie testée du cordon de soudure 62 présente un défaut d'étanchéité. Des mesures de soudure correctives sont alors mise en œuvre afin de corriger le défaut. Des mesures à l'aide d'un outil de détection complémentaire peuvent également être envisagées de manière à localiser de manière plus précise le lieu du défaut d'étanchéité.If the measured value is greater than or equal to the threshold value, then it is concluded that the tested part of the weld bead 62 has a sealing defect. Corrective welding measures are then implemented to correct the defect. Measurements using an additional detection tool can also be envisaged so as to locate more precisely the location of the sealing defect.

Ainsi, selon l'invention, la lèvre d'étanchéité 64 occupe deux positions selon qu'elle se trouve dans son état initial, soit sans l'application d'une dépression dans la chambre de détection 61, ou dans son état de service, lorsqu'une telle dépression est appliquée.Thus, according to the invention, the sealing lip 64 occupies two positions depending on whether it is in its initial state, either without the application of a vacuum in the detection chamber 61, or in its service state, when such vacuum is applied.

Dans son état initial, la lèvre d'étanchéité 64 repose sans pression sur la surface d'une membrane d'étanchéité 5, 8 tandis que dans son état de service au moins une portion de pincement 53 située à une extrémité intérieure de la lèvre d'étanchéité 64 se trouve pressée sous le corps principal 100 de manière à parfaitement étanchéifier le contour ou la périphérie de la chambre de détection 61. En effet, grâce à la souplesse de la lèvre d'étanchéité 64, celle-ci vient se pincer entre le corps principal 100 et la membrane 5, 8 lors de l'application de la dépression. Ce positionnement de la portion de pincement 53 de la lèvre d'étanchéité 64 entre le corps principal 100, écrasée ou comprimée par celui-ci, et la membrane d'étanchéité 5, 8 contribue efficacement à obtenir une parfaite étanchéité de la chambre de détection 61, permettant ainsi d'obtenir et de tenir un vide d'au plus 1500 Pa (15 mbar), voire présentant une pression bien inférieure.In its initial state, the sealing lip 64 rests without pressure on the surface of a sealing membrane 5, 8, while in its operating state at least one pinching portion 53 located at an inner end of the lip d sealing 64 is pressed under the main body 100 so as to perfectly seal the contour or the periphery of the detection chamber 61. Indeed, thanks to the flexibility of the sealing lip 64, it is pinched between the main body 100 and the membrane 5, 8 when the depression is applied. This positioning of the pinching portion 53 of the sealing lip 64 between the main body 100, crushed or compressed by the latter, and the sealing membrane 5, 8 effectively contributes to obtaining perfect sealing of the detection chamber 61, thus making it possible to obtain and maintain a vacuum of at most 1500 Pa (15 mbar), or even having a much lower pressure.

Ainsi, selon un mode d'exécution préféré, la lèvre d'étanchéité 64 présente un état de service, lorsqu'une dépression est appliquée dans la chambre de détection 61, dans lequel une portion de pincement 53 de la lèvre d'étanchéité 64 est maintenue entre le corps principal 100 et la membrane d'étanchéité 5, 8 sur au moins une partie de la périphérie de la chambre de détection 61, voire sur toute la périphérie de ladite chambre 61. Grâce à ce pincement, il est possible de se passer de tout ou partie du moyen mécanique de pression décrit plus haut.Thus, according to a preferred embodiment, the sealing lip 64 has a service state, when a vacuum is applied in the detection chamber 61, in which a pinching portion 53 of the sealing lip 64 is maintained between the main body 100 and the sealing membrane 5, 8 over at least part of the periphery of the detection chamber 61, or even over the entire periphery of said chamber 61. Thanks to this pinching, it is possible to switch from all or part of the mechanical pressure means described above.

Dans une variante de réalisation, la lèvre d'étanchéité périphérique 64 est formée avec la portion de pincement 53 faisant saillie en permanence sous le corps principal 100, c'est-à-dire également dans l'état initial sans dépression, par exemple tout autour de la chambre de détection 61 ou sur une partie de sa périphérie.In a variant embodiment, the peripheral sealing lip 64 is formed with the pinching portion 53 projecting permanently under the main body 100, that is to say also in the initial state without depression, for example while around the detection chamber 61 or over part of its periphery.

Comme indiqué plus haut, la zone à tester peut être une zone de jonction entre plusieurs tôles métalliques, par exemple quatre tôles métalliques rectangulaires, ondulées ou non. Une telle utilisation de la cloche de détection 55 va maintenant être décrite en référence aux figures 18 à 20.As indicated above, the area to be tested can be a junction area between several metal sheets, for example four rectangular metal sheets, corrugated or not. Such use of the detection bell 55 will now be described with reference to the figures 18 to 20 .

Concernant une zone de jonction entre plusieurs tôles rectangulaires planes, on peut par exemple se référer à la publication EP-A-0064886 . La publication US-A-4021982 illustre à la figure 24 une zone de jonction entre plusieurs tôles rectangulaires ondulées. Dans ces exemples comme dans celui de la figure 18, chacune des quatre tôles métalliques rectangulaires 31 comporte un pan coupé 32 au niveau du coin, par exemple formant un angle de 45° avec les bords de la tôle. Les quatre pans coupés 32 sont approchés les uns des autres à recouvrement sur un insert métallique 33 fixé sur le massif isolant et dont une zone centrale, ici de forme carrée, reste découverte entre les quatre pans coupés 32. Cette zone centrale de l'insert métallique 33 forme une partie de la membrane étanche grâce aux lignes de soudure étanches réalisées le long des pans coupés 32.Concerning a junction zone between several flat rectangular sheets, one can for example refer to the publication EP-A-0064886 . The publication US-A-4021982 illustrates the figure 24 a junction zone between several corrugated rectangular sheets. In these examples as in that of figure 18 , each of the four rectangular metal sheets 31 has a cutaway 32 at the corner, for example forming an angle of 45° with the edges of the sheet. The four cut sides 32 are approached to each other overlapping on a metal insert 33 fixed to the insulating block and of which a central zone, here of square shape, remains uncovered between the four cut sides 32. This central zone of the insert metal 33 forms part of the waterproof membrane thanks to the waterproof weld lines made along the cut sides 32.

Les lignes 34 en traits interrompus représentent des courbures de décalage dans la direction d'épaisseur des tôles métalliques rectangulaires 31 qui permettent les recouvrements mutuels, selon la technique connue.Lines 34 in dashed lines represent offset curvatures in the direction of thickness of the rectangular metal sheets 31 which allow mutual overlaps, according to the known technique.

Sur la figure 18, la cloche de détection présente une forme correspondant au mode de réalisation de la figure 13. On a esquissé la position de la cloche de détection en représentant le contour de la lèvre d'étanchéité 64 et le contour 30 de la chambre de détection 61, qui est partiellement représentée. En particulier, la zone circulaire 25 de la chambre de détection 61 est positionnée au droit de la zone de jonction précitée, par exemple centrée sur la partie découverte de l'insert métallique 33, tandis que la bande rectiligne centrale 24 de la chambre de détection 61 est positionnée sur un bord rectiligne d'une des tôles métalliques rectangulaires 31. La zone circulaire 25 de la chambre de détection 61 présente un diamètre adapté à complètement englober les quatre pans coupés 32 au droit de la zone de jonction précitée. Pour cela, son, diamètre est par exemple supérieur à 68mm pour une membrane ondulée de type Mark III®.On the figure 18 , the detection bell has a shape corresponding to the embodiment of the figure 13 . The position of the detection bell has been sketched by representing the contour of the sealing lip 64 and the contour 30 of the chamber of detection 61, which is partially shown. In particular, the circular zone 25 of the detection chamber 61 is positioned in line with the aforementioned junction zone, for example centered on the exposed part of the metal insert 33, while the central rectilinear strip 24 of the detection chamber 61 is positioned on a straight edge of one of the rectangular metal sheets 31. The circular zone 25 of the detection chamber 61 has a diameter adapted to completely encompass the four cut sides 32 in line with the aforementioned junction zone. For this, its diameter is for example greater than 68 mm for a corrugated membrane of the Mark III ® type.

Sur la figure 18, les éléments de pression d'extrémité 87 ont été esquissés en traits interrompus. On peut ainsi remarquer que les éléments de pression d'extrémité 87 ont été positionnés sur la cloche de détection de manière que, lorsque la cloche de détection est positionnée à cet emplacement, les éléments de pression d'extrémité 87 se trouvent en fait au droit des cordons de soudure 62 qui joignent les tôles métalliques rectangulaires 31 entre elles le long des bords. Ainsi, les éléments de pression d'extrémité 87 appuient sur les portions de la lèvre d'étanchéité périphérique 64 qui reposent sur ces cordons de soudure 62, lesquels présentent nécessairement un certain relief. Les éléments de pression d'extrémité 87 ainsi positionnés rendent possible l'obtention d'un contact parfaitement étanche malgré ce relief. En particulier, on voit sur la figure 18 que trois éléments de pression d'extrémité 87 appuient sur trois portions de la lèvre d'étanchéité périphérique 64 qui traversent respectivement trois cordons de soudure 62 de cette zone de jonction.On the figure 18 , the end pressure elements 87 have been sketched in dashed lines. It can thus be noted that the end pressure elements 87 have been positioned on the detection bell so that, when the detection bell is positioned at this location, the end pressure elements 87 are in fact located at right weld beads 62 which join the rectangular metal sheets 31 together along the edges. Thus, the end pressure elements 87 bear on the portions of the peripheral sealing lip 64 which rest on these weld beads 62, which necessarily have a certain relief. The end pressure elements 87 thus positioned make it possible to obtain a perfectly sealed contact despite this relief. In particular, we see on the figure 18 that three end pressure elements 87 bear on three portions of the peripheral sealing lip 64 which respectively pass through three weld beads 62 of this junction zone.

Les éléments de pression d'extrémité 87 illustrés sur la figure 18 présentent de préférence une forme allongée rectiligne ou curviligne. Ils peuvent notamment être réalisés sous la forme d'éléments d'appui allongés 91 comme sur la figure 16 ou avec une semelle de répartition 95 comme sur la figure 17.The end pressure elements 87 illustrated in the figure 18 preferably have a rectilinear or curvilinear elongated shape. They can in particular be made in the form of elongated support elements 91 as on the figure 16 or with a 95 distribution sole as on the figure 17 .

D'autres géométries de la cloche de détection peuvent être envisagées pour cette utilisation. Dans le mode de réalisation de la figure 19, la cloche de détection présente une forme modifiée dans laquelle la zone circulaire 25 constitue une portion centrale de la chambre de détection 61 et la chambre de détection 61 présente deux zones allongées 24 s'étendant depuis la zone circulaire 25 de manière diamétralement opposée l'une de l'autre le long de l'axe longitudinal médian 20. Dans le mode de réalisation de la figure 20, la cloche de détection présente une forme modifiée dans laquelle la chambre de détection 61 présente une forme circulaire.Other geometries of the detection bell can be envisaged for this use. In the embodiment of the figure 19 , the detection bell has a modified shape in which the circular zone 25 constitutes a central portion of the detection chamber 61 and the detection chamber 61 has two elongated zones 24 extending from the circular zone 25 in a diametrically opposite manner. from each other along the median longitudinal axis 20. In the embodiment of the figure 20 , the detection bell has a modified shape in which the detection chamber 61 has a circular shape.

Dans le cas de la figure 19, on voit que deux éléments de pression d'extrémité 87 appuient sur deux portions de la lèvre d'étanchéité périphérique 64 qui traversent respectivement deux cordons de soudure 62 de cette zone de jonction, à des emplacements qui sont diamétralement opposés autour de la zone circulaire 25. Dans le cas de la figure 20, on voit que quatre éléments de pression d'extrémité 87 appuient sur quatre portions de la lèvre d'étanchéité périphérique 64 qui traversent respectivement quatre cordons de soudure 62 de cette zone de jonction.In the case of the figure 19 , it can be seen that two end pressure elements 87 bear on two portions of the peripheral sealing lip 64 which cross respectively two weld beads 62 of this junction zone, at locations which are diametrically opposed around the circular zone 25. In the case of the figure 20 , it can be seen that four end pressure elements 87 bear on four portions of the peripheral sealing lip 64 which respectively pass through four weld beads 62 of this junction zone.

En variante une forme polygonale convexe peut être employée au lieu de la zone circulaire 25, auquel cas un cercle géométriquement inscrit dans la forme de la chambre de détection doit présenter un diamètre adapté à complètement englober les quatre pans coupés 32 au droit de la zone de jonction précitée.As a variant, a convex polygonal shape can be used instead of the circular zone 25, in which case a circle geometrically inscribed in the shape of the detection chamber must have a diameter adapted to completely encompass the four cut sides 32 in line with the detection zone. aforementioned junction.

En référence aux figures 22 à 25 on va maintenant décrire un mode de réalisation du dispositif de détection de fuite 54 dans lequel la cloche de détection 55 selon le quatrième mode de réalisation peut être employée.With reference to figures 22 to 25 we will now describe an embodiment of the leak detection device 54 in which the detection bell 55 according to the fourth embodiment can be used.

Le dispositif de détection de fuite 54 comporte la cloche de détection 55, l'équipement d'analyse 56 avec sa pompe à vide associée 57, éventuellement une deuxième pompe à vide 37 de plus forte puissance, et un circuit d'aspiration reliant la chambre de détection 61 à l'équipement d'analyse 56 par l'intermédiaire d'une électrovanne 48. Le circuit d'aspiration comporte de préférence un tuyau flexible 58 d'assez grande longueur pour favoriser la mobilité de la cloche de détection 55 sur une zone de travail relativement étendue autour de l'équipement d'analyse 56. Ce tuyau flexible 58 est par exemple raccordé par des connecteurs 39, d'une part à une sortie de la chambre de détection 61 et d'autre part à l'équipement d'analyse 56. Lorsqu'une deuxième pompe à vide 37 est employée, un raccord de dérivation 38 peut être prévu pour relier l'équipement d'analyse 56 et la deuxième pompe à vide 37 en dérivation l'un de l'autre.The leak detection device 54 comprises the detection bell 55, the analysis equipment 56 with its associated vacuum pump 57, possibly a second vacuum pump 37 of higher power, and a suction circuit connecting the chamber 61 to the analysis equipment 56 via a solenoid valve 48. The suction circuit preferably comprises a flexible pipe 58 of sufficient length to promote the mobility of the detection bell 55 on a relatively large work area around the analysis equipment 56. This flexible pipe 58 is for example connected by connectors 39, on the one hand to an outlet of the detection chamber 61 and on the other hand to the equipment 56. When a second vacuum pump 37 is employed, a branch connection 38 may be provided to connect the analysis equipment 56 and the second vacuum pump 37 in branch from each other.

Une unité de commande 36 est également prévue pour piloter l'électrovanne 48, et éventuellement d'autres éléments comme l'équipement d'analyse 56, en réponse à des actions d'un opérateur sur un ou plusieurs organes de commande de la cloche de détection 55, par exemple disposés sur une ou plusieurs poignées de manutention 76 de la cloche de détection 55.A control unit 36 is also provided to drive the solenoid valve 48, and possibly other elements such as the analysis equipment 56, in response to actions by an operator on one or more detection 55, for example arranged on one or more handling handles 76 of the detection bell 55.

Par exemple, dans le cas de la cloche de détection 55 selon le quatrième mode de réalisation, les deux poignées de manutention 76 sont munies chacune d'un bouton poussoir actionnable avec le pouce et configuré respectivement comme bouton d'activation 51 et bouton de désactivation 52. Des organes de commande présentant une autre forme qu'une bouton poussoir peuvent être envisagées alternativement, par exemple un bouton tactile capacitif, un levier basculant, ou tout autre organe actionnable manuellement.For example, in the case of the detection bell 55 according to the fourth embodiment, the two handling handles 76 are each provided with a push button operable with the thumb and configured respectively as an activation button 51 and a deactivation button 52. Control members having a shape other than a push button can be considered alternatively, for example a capacitive touch button, a tilting lever, or any other manually operable member.

Dans un mode de fonctionnement préféré, la pompe à vide 37 ou autre source de dépression est préalablement activée et génère de manière permanente une dépression dans le circuit d'aspiration. L'électrovanne 48 présente un état fermé par défaut, de sorte que la chambre de détection 61 n'est pas initialement soumise à la dépression, ce qui permet de déplacer librement la cloche de détection 55 sur la membrane 5, 8.In a preferred mode of operation, the vacuum pump 37 or other source of depression is activated beforehand and permanently generates a depression in the suction circuit. The solenoid valve 48 has a closed state by default, so that the detection chamber 61 is not initially subjected to the depression, which makes it possible to move the detection bell 55 freely on the membrane 5, 8.

Partant de cet état, les procédés de commande illustrés sur les figures 23 et 24 peuvent être mis en œuvre par l'unité de commande 36 :Starting from this state, the control methods illustrated on the figures 23 and 24 can be implemented by the control unit 36:

A l'étape 41, un signal de commande d'activation émis par le bouton d'activation 51 est détecté.At step 41, an activation command signal issued by the activation button 51 is detected.

A l'étape 42, l'électrovanne 48 est commutée dans un état ouvert pour relier la chambre de détection 61 à la pompe à vide 37. Cet état peut être signalé par l'allumage d'un indicateur lumineux sur la cloche de détection 55, par exemple une LED rouge, par exemple sur la poignée de manutention 76 comme illustré au chiffre 96 de la figure 15.In step 42, the solenoid valve 48 is switched to an open state to connect the detection chamber 61 to the vacuum pump 37. This state can be signaled by the lighting of a luminous indicator on the detection bell 55 , for example a red LED, for example on the handling handle 76 as shown in figure 96 of the figure 15 .

Il se produit alors une aspiration dans la chambre de détection 61. Si la cloche de détection 55 est correctement positionnée sur la membrane avec la lèvre d'étanchéité 24 en contact étanche avec la membrane 5, 8 tout autour de la chambre de détection 61, la dépression s'installe et plaque solidement la cloche de détection 55 contre la membrane 5, 8 en écrasant la lèvre d'étanchéité 24. L'analyse du gaz issu de la chambre de détection 61 peut alors être effectuée comme expliqué plus haut.A suction then occurs in the detection chamber 61. If the detection bell 55 is correctly positioned on the membrane with the sealing lip 24 in tight contact with the membrane 5, 8 all around the detection chamber 61, the vacuum sets in and firmly presses the detection bell 55 against the membrane 5, 8 by crushing the sealing lip 24. The analysis of the gas issuing from the detection chamber 61 can then be carried out as explained above.

A l'étape 45, un signal de commande de désactivation émis par le bouton de désactivation 52 est détecté.At step 45, a disable command signal from disable button 52 is detected.

A l'étape 46, l'électrovanne 48 est commutée dans un état fermé pour isoler la chambre de détection 61 de la pompe à vide 37. La dépression dans la chambre de détection 61 n'est plus entretenue, ce qui permet à la pression de remonter. Toutefois, sauf débit de fuite important, cette remontée de la pression peut être très lente.At step 46, the solenoid valve 48 is switched to a closed state to isolate the detection chamber 61 from the vacuum pump 37. The depression in the detection chamber 61 is no longer maintained, which allows the pressure to go up. However, unless there is a large leak rate, this rise in pressure can be very slow.

De préférence, à l'étape 47, un évent est donc ouvert pour mettre en communication la chambre de détection 61 avec l'atmosphère ambiante, ce qui permet de libérer immédiatement la cloche de détection 55 de la membrane 5, 8.Preferably, in step 47, a vent is therefore opened to place the detection chamber 61 in communication with the ambient atmosphere, which makes it possible to immediately release the detection bell 55 from the membrane 5, 8.

Dans un mode de réalisation, les étapes 46 et 47 sont effectuées simultanément en commutant une vanne à trois voies 148 schématisée sur la figure 25, qui est utilisée à la place de l'électrovanne 48 de la figure 22.In one embodiment, steps 46 and 47 are performed simultaneously by switching a three-way valve 148 shown schematically on the figure 25 , which is used instead of solenoid valve 48 of the figure 22 .

L'électrovanne 48 peut être positionnée sur la sortie de gaz 78 de la cloche de détection 55, comme illustré sur la figure 22. Elle peut aussi être positionnée à un autre emplacement dans le circuit d'aspiration, par exemple au niveau du raccord de dérivation 38 comme indiqué par le chiffre 248.The solenoid valve 48 can be positioned on the gas outlet 78 of the detection bell 55, as illustrated in the figure 22 . It can also be positioned at another location in the suction circuit, for example at the branch connection 38 as indicated by the number 248.

Les signaux de commande entre l'unité de commande 36, l'électrovanne 48 et les bouton d'activation 51 et bouton de désactivation 52 sont transportés par des liaisons de communication 35 filaires ou non filaires, par exemple réalisée sous la forme d'une câble électrique souple ou une tresse de câbles souples pour favoriser la mobilité de la cloche de détection 55.The control signals between the control unit 36, the solenoid valve 48 and the activation button 51 and deactivation button 52 are transported by wired or wireless communication links, for example made in the form of a flexible electrical cable or a braid of flexible cables to promote the mobility of the detection bell 55.

Dans un mode de réalisation, l'unité de commande 36 est configurée pour piloter aussi l'équipement d'analyse 56. Pour cela, une liaison de communication 35 filaire ou non filaire est également prévue entre l'unité de commande 36 et l'équipement d'analyse 56. De plus, un capteur de pression 49 également relié à l'unité de commande 36 est prévu sur la cloche de détection 55 pour mesurer la pression dans la chambre de détection 61 à la suite de l'étape 42.In one embodiment, the control unit 36 is configured to also control the analysis equipment 56. For this, a wired or wireless communication link 35 is also provided between the control unit 36 and the analysis equipment 56. In addition, a pressure sensor 49 also connected to the control unit 36 is provided on the detection bell 55 to measure the pressure in the detection chamber 61 following step 42.

Dans ce cas, le procédé de commande réalisé à la suite du signal de commande d'activation se poursuit de la manière suivante :In this case, the control process carried out following the activation control signal continues as follows:

A l'étape 43 la pression indiquée par le signal de mesure du capteur de pression 49 est comparée à un seuil de pression prédéfini pour permettre le fonctionnement de l'équipement d'analyse 56. Si la pression mesurée est inférieure à ce seuil, l'étape 44 est effectuée. Cet état peut être signalé par l'allumage d'un autre indicateur lumineux sur la cloche de détection 55, par exemple une LED verte, par exemple sur la poignée de manutention 76 comme illustré au chiffre 97 de la figure 15.In step 43, the pressure indicated by the measurement signal from the pressure sensor 49 is compared with a predefined pressure threshold to allow the operation of the analysis equipment 56. If the pressure measured is lower than this threshold, the step 44 is performed. This state can be signaled by the lighting of another luminous indicator on the detection bell 55, for example a green LED, for example on the handling handle 76 as illustrated in figure 97 of the figure 15 .

A l'étape 44 l'équipement d'analyse 56 est activé pour réaliser un cycle d'analyse permettant de détecter un débit de fuite, comme expliqué plus haut.In step 44 the analysis equipment 56 is activated to carry out an analysis cycle making it possible to detect a leak rate, as explained above.

Dans le cas de la cloche de détection selon le quatrième mode de réalisation illustrée à la figure 13 ou 21, deux canaux 82 et 50 traversent le corps principal pour relier la chambre de détection 61 à deux sorties de gaz 78 et 50. Le capteur de pression 49 peut être placé sur la cloche de détection 55 été relié à la sortie de gaz 50, comme illustré sur la figure 22. Le capteur de pression 49 pourrait aussi être agencé à une autre position.In the case of the detection bell according to the fourth embodiment illustrated in figure 13 Where 21 , two channels 82 and 50 pass through the main body to connect the detection chamber 61 to two gas outlets 78 and 50. The pressure sensor 49 can be placed on the detection bell 55 and connected to the gas outlet 50, as illustrated on the figure 22 . The pressure sensor 49 could also be arranged at another position.

Grâce aux procédés de commande décrits ci-dessus, et en particulier avec la cloche de détection selon le quatrième mode de réalisation, l'utilisation du dispositif de détection de fuite 54 est particulièrement aisée et rapide.Thanks to the control methods described above, and in particular with the detection bell according to the fourth embodiment, the use of the leak detection device 54 is particularly easy and rapid.

La source de dépression étant préalablement activé, l'opérateur saisit la cloche de détection 55 par les deux poignées et positionne la cloche de détection 55 sur la zone de test choisie, le cas échéant en s'aidant des dispositifs de visée décrits plus haut.The source of depression being activated beforehand, the operator grasps the detection bell 55 by the two handles and positions the detection bell 55 on the chosen test zone, if necessary with the help of the sighting devices described above.

Puis l'opérateur presse le bouton d'activation 51. Le procédé de la figure 23 s'exécute alors jusqu'à obtention d'une mesure représentative du débit de fuite par l'équipement d'analyse 56.Then the operator presses the activation button 51. The process of the figure 23 then runs until a representative measurement of the leak rate is obtained by the analysis equipment 56.

L'opérateur n'a plus qu'à presser le bouton de désactivation 52 pour positionner la cloche de détection 55 sur une autre zone de test. La cloche de détection 55 peut donc être employée sans que l'opérateur n'ait besoin d'interagir avec la pompe à vide 37, l'unité de commande 36 ou l'équipement d'analyse 56, dans toute une zone de travail définie par la longueur des liaisons fluidiques et électriques de la cloche de détection 55 avec ces éléments. Pour favoriser la mobilité du dispositif de détection de fuite 54 à une plus grande échelle, la pompe à vide 37, l'unité de commande 36 et l'équipement d'analyse 56 peuvent être montés sur un chariot roulant, non illustré.The operator only has to press the deactivation button 52 to position the detection bell 55 on another test zone. The detection bell 55 can therefore be used without the operator needing to interact with the vacuum pump 37, the control unit 36 or the analysis equipment 56, in an entire defined work area. by the length of the fluidic and electrical connections of the detection bell 55 with these elements. To promote the mobility of the leak detection device 54 on a larger scale, the vacuum pump 37, the control unit 36 and the analysis equipment 56 can be mounted on a rolling cart, not shown.

Dans un autre mode de réalisation non représenté, les différentes caractéristiques des modes de réalisation précédents sont combinables entre elles. En effet par exemple, les moyens mécaniques de pression 66 de la figure 8 sont adaptables à un joint d'étanchéité 60 de la figure 5 en modifiant l'agencement des lames courbées 72.In another embodiment not shown, the different characteristics of the previous embodiments can be combined with one another. Indeed, for example, the mechanical pressure means 66 of the figure 8 are adaptable to a gasket 60 of the figure 5 by modifying the arrangement of the curved blades 72.

La cloche de détection, le dispositif de détection et le procédé d'utilisation du dispositif décrits ci-dessus visent plus particulièrement à tester l'étanchéité d'une membrane d'une cuve étanche et thermiquement isolante à membranes. A titre d'exemple, de telles cuves à membranes sont notamment décrites dans les demandes de brevet WO14057221 , FR2691520 .The detection bell, the detection device and the method of using the device described above are aimed more particularly at testing the tightness of a membrane of a sealed and thermally insulating tank with membranes. By way of example, such membrane tanks are described in particular in the patent applications WO14057221 , FR2691520 .

Les cuves à membrane présentent une pluralité de parois qui présentent une structure multicouche, telle que représentée sur la figure 11. Chaque paroi 1 comporte, depuis l'extérieur vers l'intérieur de la cuve, une barrière thermiquement isolante secondaire 2 comportant des panneaux isolants secondaires 3 ancrés à une structure porteuse 4, une membrane secondaire 5 reposant contre la barrière thermiquement isolante secondaire 2, une barrière thermiquement isolante primaire 6 comportant des panneaux isolants primaires 7 reposant contre la membrane secondaire 2 et ancrés à la structure porteuse 4 ou aux panneaux isolants secondaires 3 et une membrane primaire 8 qui repose contre la barrière thermiquement isolante primaire 6 et qui est destinée à être en contact avec le gaz liquéfié contenu dans la cuve.Membrane tanks have a plurality of walls that have a multi-layered structure, as shown in the figure 11 . Each wall 1 comprises, from the outside towards the inside of the tank, a secondary thermally insulating barrier 2 comprising secondary insulating panels 3 anchored to a supporting structure 4, a secondary membrane 5 resting against the secondary thermally insulating barrier 2, a primary thermally insulating barrier 6 comprising primary insulating panels 7 resting against the secondary membrane 2 and anchored to the load-bearing structure 4 or to the secondary insulating panels 3 and a primary membrane 8 which rests against the primary thermally insulating barrier 6 and which is intended to be in contact with the liquefied gas contained in the tank.

La cuve présente une forme générale polyédrique. Dans le mode de réalisation illustré sur la figure 12, la cuve présente une paroi avant 9 et une paroi arrière, non représentée, qui sont ici de forme octogonale. La cuve comporte également une paroi de plafond 10, une paroi de fond 11 et des parois latérales 11, 12, 13, 14, 15, 16, 17 qui s'étendent selon la direction longitudinale de la cuve entre la paroi avant 9 et la paroi arrière.The tank has a generally polyhedral shape. In the embodiment illustrated in the figure 12 , the tank has a front wall 9 and a rear wall, not shown, which are octagonal in shape here. The tank also comprises a ceiling wall 10, a bottom wall 11 and side walls 11, 12, 13, 14, 15, 16, 17 which extend along the longitudinal direction of the tank between the front wall 9 and the rear wall.

Les barrières thermiquement isolantes secondaires 2 des parois de cuve communiquent les unes avec les autres de manière à former, entre la structure porteuse 4 et la membrane secondaire 5, un espace thermiquement isolant secondaire, étanche. De même, les barrières thermiquement isolantes primaires 6 des parois de cuve communiquent les unes avec les autres de manière à former, entre la membrane secondaire 5 et la membrane primaire 8, un espace thermiquement isolant primaire, étanche.The secondary thermally insulating barriers 2 of the vessel walls communicate with each other so as to form, between the supporting structure 4 and the secondary membrane 5, a secondary thermally insulating, sealed space. Similarly, the primary thermally insulating barriers 6 of the vessel walls communicate with each other so as to form, between the secondary membrane 5 and the primary membrane 8, a primary, sealed, thermally insulating space.

Au moins l'une des membranes primaire 8 et secondaire 5 comporte une pluralité de tôles métalliques qui sont soudées les unes aux autres. Le procédé de test d'étanchéité qui sera décrit par la suite vise plus particulièrement à tester l'étanchéité des soudures permettant de raccorder les tôles métalliques les unes aux autres. Selon un mode de réalisation, la membrane à tester présente des ondulations qui lui permettent de se déformer sous l'effet des sollicitations thermiques et mécaniques générées par le fluide emmagasiné dans la cuve. Pour ce faire, comme représenté par exemple sur la figure 8, chaque tôle métallique comporte deux séries d'ondulations perpendiculaires l'une à l'autre.At least one of the primary 8 and secondary 5 membranes comprises a plurality of metal sheets which are welded to each other. The tightness test method which will be described later aims more particularly at testing the tightness of the welds making it possible to connect the metal sheets to each other. According to one embodiment, the membrane to be tested has undulations which allow it to deform under the effect of the thermal and mechanical stresses generated by the fluid stored in the tank. To do this, as shown for example in the figure 8 , each metal sheet has two sets of corrugations perpendicular to each other.

Dans un mode de réalisation, le procédé de test d'étanchéité comporte trois étapes, à savoir :

  • la diffusion d'un gaz traceur dans un espace thermiquement isolant recouvert par la membrane 5, 8 dont on souhaite tester l'étanchéité ;
  • le contrôle de la diffusion du gaz traceur dans l'espace thermiquement isolant ; et
  • la vérification de l'étanchéité des soudures de la membrane 5, 8.
In one embodiment, the leak test method comprises three steps, namely:
  • the diffusion of a tracer gas in a thermally insulating space covered by the membrane 5, 8 whose tightness is to be tested;
  • control of the diffusion of the tracer gas in the thermally insulating space; and
  • checking the tightness of the welds of the membrane 5, 8.

Dans un autre mode de réalisation, le procédé de test d'étanchéité comporte seulement la vérification de l'étanchéité des soudures de la membrane 5, 8 sans l'aide de gaz traceur.In another embodiment, the sealing test method comprises only the verification of the sealing of the welds of the membrane 5, 8 without the aid of tracer gas.

L'étape de diffusion d'un gaz traceur consiste à injecter un gaz traceur dans l'espace thermiquement isolant qui est recouvert par la membrane 5, 8 dont on souhaite vérifier l'étanchéité. Lorsque l'on souhaite vérifier l'étanchéité de la membrane secondaire 5, le gaz traceur est injecté dans l'espace thermiquement isolant secondaire. Dans ce cas, le procédé de test d'étanchéité est mis en œuvre avant que la barrière thermiquement isolante primaire 7 et la membrane primaire 8 ne soient installées. Lorsque l'on souhaite vérifier l'étanchéité de la membrane primaire 8, le gaz traceur est injecté dans l'espace thermiquement isolant primaire.The step of diffusion of a tracer gas consists in injecting a tracer gas into the thermally insulating space which is covered by the membrane 5, 8 whose tightness is to be checked. When it is desired to check the tightness of the secondary membrane 5, the tracer gas is injected into the secondary thermally insulating space. In this case, the sealing test method is implemented before the primary thermally insulating barrier 7 and the primary membrane 8 are installed. When it is desired to check the tightness of the primary membrane 8, the tracer gas is injected into the primary thermally insulating space.

La figure 12 illustre schématiquement une cuve étanche et thermiquement isolante ainsi qu'un système d'injection du gaz traceur dans un espace thermiquement isolant.The figure 12 schematically illustrates a sealed and thermally insulating tank as well as a system for injecting tracer gas into a thermally insulating space.

Le système d'injection comporte une pluralité de conduits 18 qui sont, d'une part, reliés à une source de gaz traceur, non illustrée, et, d'autre part, reliés à des dispositifs d'injection du gaz traceur 19 ménageant un passage d'injection du gaz traceur au travers de la membrane 5, 8 dont l'étanchéité doit être testée. Plus particulièrement, les dispositifs d'injection du gaz traceur 19 ménagent des passages de gaz traceur au travers de la membrane de la paroi de fond 11. Une telle disposition est particulièrement avantageuse car le gaz traceur présente une densité de vapeur plus faible que celle de l'air de sorte qu'il a tendance à monter dans l'espace thermiquement isolant. Dès lors, l'injection du gaz traceur par le bas, au travers de la membrane 5, 8 à tester de la paroi de fond 11, permet d'assurer une diffusion rapide et homogène du gaz traceur dans l'espace thermiquement isolant.The injection system comprises a plurality of ducts 18 which are, on the one hand, connected to a source of tracer gas, not shown, and, on the other hand, connected to tracer gas injection devices 19 providing a injection passage of the tracer gas through the membrane 5, 8 whose tightness must be tested. More particularly, the tracer gas injection devices 19 provide tracer gas passages through the membrane of the bottom wall 11. Such an arrangement is particularly advantageous because the tracer gas has a lower vapor density than that of the air so that it tends to rise in the thermally insulating space. Consequently, the injection of the tracer gas from below, through the membrane 5, 8 to be tested of the bottom wall 11, makes it possible to ensure rapid and homogeneous diffusion of the tracer gas in the thermally insulating space.

Dans le mode de réalisation représenté sur la figure 12, la paroi de fond 11 est équipée d'au moins quatre dispositifs d'injection du gaz traceur 19 qui sont régulièrement répartis sur la surface de la paroi de fond 11. La paroi de fond 11 présente une forme rectangulaire et peut ainsi être divisée en quatre zones de surface égale par ses deux axes de symétrie x et y. Chacun des quatre dispositifs d'injection du gaz traceur 19 est disposé dans l'une des quatre zones précitées. Dans le mode de réalisation particulier illustré, chaque dispositif d'injection du gaz traceur 19 est disposé à proximité du centre de sa zone respective. Dans un mode de réalisation particulier, chacun des quatre dispositifs d'injection du gaz traceur est disposé à une distance ¼ L du bord longitudinal adjacent et à une distance ¼ B du bord transversal adjacent avec L : la dimension longitudinale de la paroi de fond 11 et B : la dimension transversale de la paroi de fond 11.In the embodiment shown in the figure 12 , the bottom wall 11 is equipped with at least four tracer gas injection devices 19 which are evenly distributed over the surface of the bottom wall 11. The bottom wall 11 has a rectangular shape and can thus be divided into four zones of equal surface by its two axes of symmetry x and y. Each of the four tracer gas injection devices 19 is placed in one of the four aforementioned zones. In the particular embodiment illustrated, each tracer gas injection device 19 is arranged close to the center of its respective zone. In a particular embodiment, each of the four tracer gas injection devices is arranged at a distance ¼ L from the adjacent longitudinal edge and at a distance ¼ B from the adjacent transverse edge with L: the longitudinal dimension of the bottom wall 11 and B: the transverse dimension of the bottom wall 11.

L'étape de contrôle de diffusion de gaz traceur consiste à lorsque le gaz traceur a diffusé au travers de l'espace thermiquement isolant, contrôler la diffusion du gaz traceur dans l'espace thermiquement isolant.The tracer gas diffusion control step consists in, when the tracer gas has diffused through the thermally insulating space, controlling the diffusion of the tracer gas in the thermally insulating space.

Pour ce faire, l'on prélève le gaz contenu dans l'espace thermiquement isolant dans lequel l'on a injecté le gaz traceur au moyen d'une pluralité de dispositifs de prélèvement de gaz ménagés au travers de la membrane recouvrant ledit espace thermiquement isolant. Chaque dispositif de prélèvement est relié à un équipement d'analyse, tel qu'un spectromètre de masse, qui permet de vérifier la présence et la concentration du gaz traceur dans la zone correspondante de l'espace thermiquement isolant.To do this, the gas contained in the thermally insulating space into which the tracer gas has been injected is sampled by means of a plurality of gas sampling devices provided through the membrane covering said thermally insulating space. . Each sampling device is connected to analysis equipment, such as a mass spectrometer, which makes it possible to verify the presence and the concentration of the tracer gas in the corresponding zone of the thermally insulating space.

L'étape de vérification des soudures consiste à utiliser le dispositif de détection de fuite 54, précédemment décrit, sur l'une des membranes 5, 8 de la cuve étanche et thermiquement isolante.The weld verification step consists of using the leak detection device 54, previously described, on one of the membranes 5, 8 of the sealed and thermally insulating tank.

Claims (13)

  1. A leak detection device (54) for detecting a leak in a test zone (62) of a sealing membrane (5, 8) of a sealed and thermally insulating tank, the leak detection device (54) including:
    - a leak detection dome (55) including a main body (100) intended to be disposed in the test zone (62) and a seal (60) connected to the main body (100) and configured to define a detection chamber (61) between the main body (100) and the test zone (62), the seal (60) including a peripheral sealing lip (64) configured to come into contact with the sealing membrane and having a closed contour encircling the detection chamber (61),
    - a vacuum pump (57) connected to the detection chamber (61) to generate a reduced pressure in the detection chamber (61), and
    - an analysis tool (56) connected to the detection chamber (61) to analyze a gas present in the detection chamber (61),
    in which the sealing lip (64) is configured to occupy two positions, namely a first position in an initial state, without application of a vacuum in the detection chamber (61), and a second position in a service state, with application of a vacuum in the detection chamber (61), characterized in that the sealing lip (64) comprises only in the second position relative to the service state a pinch portion (53) that is pinched between the main body (100) and the sealing membrane (5, 8) over at least a part of the periphery of the detection chamber (61), the sealing lip (64) having a flexibility allowing the formation of said pinch portion (53) by deformation of the sealing lip (64) towards the detection chamber (61) under the effect of the depression in the detection chamber (61).
  2. The device as claimed in claim 1, in which the sealing lip (64) is configured to have, at least in a service state in which a reduced pressure is applied in the detection chamber (61), a pinch portion (53) that is pinched between the main body (100) and the sealing membrane (5, 8) over all of the periphery of the detection chamber (61).
  3. The device as claimed in any one of claims 1 to 2, in which the detection chamber (61) of the leak detection dome (55) has a convex, for example circular or polygonal, zone (25) intended to cover a junction zone between four corrugated or plane metal plates (31).
  4. The device as claimed in claim 3, in which a circle geometrically inscribed in the convex zone (25) has a diameter greater than 68 mm.
  5. The device as claimed in claim 3 or 4, in which the detection dome has an elongate shape along a longitudinal axis, the detection chamber (61) of the leak detection dome (55) including an elongate zone (24) intended to cover a rectilinear edge of a metal plate, the convex zone (25) being disposed at one end of the elongate zone.
  6. The device as claimed in claim 5, in which the convex zone is a first convex zone (25) and the detection chamber (61) of the leak detection dome (55) includes a second convex zone disposed at an end of the elongate zone opposite the first convex zone (25) along the longitudinal axis.
  7. The device as claimed in claim 3 or 4, in which the detection dome has an elongate shape along a longitudinal axis, the convex zone (25) constituting a central portion of the detection chamber (61) of the leak detection dome (55), the detection chamber (61) including two elongate zones (24) extending from the convex zone away from one another along the longitudinal axis.
  8. The device as claimed in claim 3, in which the detection chamber (61) has a convex polygonal or circular shape.
  9. The device as claimed in claim 8, in which a circle geometrically inscribed in the shape of the detection chamber has a diameter greater than 68 mm.
  10. The device as claimed in any one of claims 1 to 9, in which the leak detection dome (55) includes a mechanical pressure means (66) carried by the main body (100) and including at least one pressure element (72) configured to exert on a portion of the sealing lip (64) a pressure directed toward the membrane (5, 8) when the main body (100) is disposed in the test zone (62).
  11. The device as claimed in any one of claims 1 to 10, in which the analysis tool (56) is configured to detect a tracer gas.
  12. The device as claimed in any one of claims 1 to 10, in which the analysis tool (56) is configured to detect a component of the surrounding air.
  13. A method of using a leak detection device (54) as claimed in any one of claims 1 to 12 in combination with claim 3 in a test zone (62) including a junction zone between four corrugated or plane metal plates (31) of a tank sealing membrane (5, 8), the method including the steps of:
    - placing the leak detection dome (55) in the test zone (62) in such a manner that the sealing lip (64) comes into contact with the sealing membrane all around the test zone (62) and the convex zone (25) covers said junction zone,
    - generating a reduced pressure in the detection chamber (61) by means of the vacuum pump (57),
    - pinching the pinch portion of the sealing lip (64) between the main body (100) and the sealing membrane (5, 8) over at least a part of the periphery of the detection chamber (61),
    - conveying the gases present in the detection chamber (61) toward the analysis tool (56), and
    - analyzing by means of the analysis tool (56) the gases coming from the detection chamber (61) to produce a measurement signal representing a quantity of at least one gas present in the detection chamber (61).
EP19740609.3A 2018-05-22 2019-05-21 Leak detection device Active EP3797276B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR1870586A FR3079300B1 (en) 2018-03-21 2018-05-22 LEAK DETECTION BELL FOR SEALING MEMBRANE
PCT/FR2019/050623 WO2019180373A1 (en) 2018-03-21 2019-03-19 Bell-shaped leak detection device for a sealing membrane
PCT/FR2019/051157 WO2019224475A2 (en) 2018-05-22 2019-05-21 Leak detection device

Publications (2)

Publication Number Publication Date
EP3797276A2 EP3797276A2 (en) 2021-03-31
EP3797276B1 true EP3797276B1 (en) 2022-08-31

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CN (1) CN112469983B (en)
SG (1) SG11202011372RA (en)
WO (1) WO2019224475A2 (en)

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FR3115880B1 (en) * 2020-10-29 2023-05-26 Gaztransport Et Technigaz Leak test device for a sealed and thermally insulating tank membrane and associated leak detection method
CN114397067A (en) * 2021-12-29 2022-04-26 中国原子能科学研究院 Leak detection device and leak detection method

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CN112469983B (en) 2023-07-11
SG11202011372RA (en) 2020-12-30
WO2019224475A2 (en) 2019-11-28
CN112469983A (en) 2021-03-09
WO2019224475A3 (en) 2020-01-30
EP3797276A2 (en) 2021-03-31

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